Summary of The Transactions – The 1980s
For the tin mining industry the 1980s started with a continuation of the prosperity of the previous decade and with every indication of this continuing. However, the world-wide price of tin was being held at an artificially high level which could not be sustained and eventually the agreements started to collapse and in 1985 the price dropped from over £10,000 per ton to £3,400. At this level none of the Cornish mines could survive without considerable aid. There were protracted negotiations with the UK Government. Some support was offered which helped to keep a few of the larger mines surviving for a few more years but the 1980s could be described as the final cliff over which tin mining finally fell as a major Cornish industry.
The china clay industry had also seen considerable change much of it following the need to mechanise both the extraction and processing operations. This inevitably led to some decrease in the labour force but the level of production remained almost unchanged.
The engineering industry also underwent considerable contraction in the 1980s. Compair Holman decreased in size by stages with production of rock drills ending in 1985 and by the end of the decade the Company was very near to closure.
The President for the session was Mr. A.D. Bennetts and there were six General Meetings two of which were held jointly with the Minerals Engineering Society and one jointly with the Royal Geological Society of Cornwall. In addition to these the 17th Annual Symposium and the Annual General Meeting were held. Unfortunately no copies have been found of the texts of these lectures.
The first General Meeting on 24th October 1980 was a joint meeting with the Royal Geological Society of Cornwall to hear a lecture by Mr. C. Bristow on “The Volcanoes of the Kenya Rift Valley”.
The 17th Annual Symposium was held on 22nd October when the subject was “Energy in the 80s”
The second General Meeting on 12th November was held jointly with the Minerals Engineering Society at the ECLP Research Laboratories Lecture Theatre when four short papers were presented by Society and Institute members.
The third General Meeting on 10th December was given a talk by Mr. R. Craddock, Exploration of UK Inc. on the subject of “Mine Feasibility Studies.
The fourth General Meeting on 21 January 1981 had a talk on “Tin Streaming in Waldron” given by Mr. J. Brooke.
A joint General Meeting with the Minerals Engineering Society was held on 18th February when Dr. J. D. Scantlebury, University of Manchester Institute of Science and Technology, gave a talk on “Corrosion in Engineering.
The sixth General Meeting on 18th March had talk on “Thermal Environment in Underground Mining” which was given by Mr. M. Howes of CSM.
The Annual General Meeting was held on 29th April and, following the formal business, Dr. P. Hacket gave lecture on “The Engineer in Society.
No records for this session have been found although a newsletter distributed in September 1983 apologised for the fact that it had not been possible to print Volume XXXII of the Transactions and in fact Transactions have never been published since that time. This Newsletter did however contained a Statement of Accounts for 1982 they showed that the bank balance on 1st January was £871.94, Subscriptions amounted to £664, Symposium fees were £402, Payments for a visit to Goonhilly and bank interest was £66.63 . Expenses included £387.70 for Symposium costs, The Goonhilly visit cost £37.50 and Secretary’s expenses for 1981 and 1982 which included including printing costs came to £205.65. The bank balance on 31st December was £1426.22. The William Thomas Memorial Fund contained £148.83 on 1st January and with bank interest and dividends the balance stood at £159.90
The President for this session was Mr. T. Andrews and the programme include the 18th Annual Symposium and six General Meetings two of which were held jointly with the Minerals Engineering Society and one with the Royal Geological Society of Cornwall.
There 18th Annual Symposium on 29th September was held at the Camborne School of Mines and covered variety of subjects of interest in the modern mining industry. Following the opening of the Symposium by Mr. D Penhaligon, MP the Chairman for the first set of papers, on Mining Feasibility Studies, was Mr. G.J. Shrimpton who introduced two speakers. Mr. B Baverstock, Senior Consultant (Mining) and Mr. J Simpson, Senior Mining Engineer who both work for Seltrust Engineering Ltd. They jointly presented a paper on “Mining Feasibility Studies” in which they examined the engineering aspects of mine design and looked at the various options available. To keep the study within bounds they confined themselves to small and medium sized underground operations typical of the deposits in SW England.
After a short break there were two parallel sessions, one on General Safety in Mines chaired by Mr. R.H. Stapleton and the other on Current Research in the Fields of Tin Consumption chaired by Mr. G.C. Pengilly. The speaker on Mine Safety was Mr. M.B. Jones, Deputy Chief Inspector of Mines and Quarries who concentrated on Miscellaneous Mines and made comparison with accidents in coal mines.
The Speaker on Current Research in Tin Consumption was Mr. B.T.K. Barry, Assistant Director of The International Tin Research Institute. He said research ranged from improvements to current uses such as tin plate to modern industrial applications in the chemical industry.
Following a lunch break the symposium once again divided into two groups; one on Advances in Surface and Underground Surveying chaired by Mr. M.B. Shipp and the other on Superconductivity & Magnetic Separation chaired by Mr. C. V. Phillips. The speaker on Surveying was Mr. R. Pendlington, Regional Sales Manager of Wild Heerbrugg (UK) Ltd. whose talk covered the rapid advances made in surveying techniques and equipment in the preceding two decades and showed some of the equipment made by his company.
The speaker in the other group was Mr. J.H.P. Watson of the Institute of Cryogenics at Southampton University. His talk described the use of superconductive magnets for the magnetic separation of industrial minerals. He described some projects and gave details of machine suitable for laboratory and and pilot scale work.
The closing session on the Environmental Aspects of Mine Planning was chaired by Dr. P. Hacket and the speaker was Mr. J. Stocks, Royal School of Mines. He spoke about the major effect of Town and Country Planning applications and Public Enquiries which can often be very lengthy, emotive and costly. He showed how environmental constraints have to be integrated into planning studies.
After the successful symposium the first General Meeting on 20th October was held jointly with the Minerals Engineering Society at the ECLP Research Laboratories when there was a talk given by Mr. S. Shaw of the N.C.B. Research and Development Establishment on the subject of “The Rotating Probability Screen.”
The second General Meeting on 17th November was addressed by Mr. K.H. Thompson speaking about “Computer Simulation and Management”.
The third General Meeting on 15th December was on an allied subject when a speaker from Control Data Ltd. spoke on “Computer Aided Design”.
The fourth General Meeting, the first in1983, was held on 19th January when Mr. J. Turner, CSM, spoke about “Tin Mining – Britain and Malaysia”
The fifth General Meeting, held jointly with the Minerals Engineering Society on 23rd February heard a talk on “Management Strategy at South Crofty” given by Dr. J.J.P. Gooden, Director of Hyrosearch Associates Ltd.”
The fifth General Meeting on 23rd March was held jointly with the Royal Geological Society of Cornwall when the subject of a talk by Mr. J.J.P. Gooden, Director of Hydrosearch Associates Ltd. was “Offshore Geophysics”.
The Annual General Meeting was held on 27th April but there is no report of the proceeding although a statement of the accounts for 1982 was published in a newsletter at the end of 1983.
These showed that the bank balance on 1st January was £871.94. Income during the year included £664 from current and arrear subscriptions. £402 from 1981 symposium attendance, £40.50 from Goonhilly visit payments and £66.63 from Bank Interest. Expenditure included £387 70 for symposium costs, £78.65 Secretarial Expenses for 1981& 1982 and £27.00 printing costs. The balance on 31st December was £1426.22. The William Thomas Memorial Fund had a balance of £148.83 on 1st January and received £11.07 from dividends and bank interest giving a balance of £159.90 on 31st December.
Following the formal business Mr. K.A. Gilbert, Managing Director of Geevor Tin Mines plc was invited to give a talk on “Operations at Geevor”.
The President for the session was Mr. L.J.Bullen who took over from Mr. Andrews at the Annual Dunner and there were two summer visits and seven General Meetings two of which were held jointly with the Minerals Engineering Society and one jointly with the Royal Geological Society of Cornwall. In addition to these the Annual Symposium and the Annual General Meeting were held.
The first General Meeting on 14th September 1983 was the occasion for the Presidential Address by Mr. L.J. Bullen. The Secretary’s report for the session noted that there was a very poor attendance for a very interesting address but unfortunately gave no details of the content.
The next event in the calendar was the Annual Symposium on the 28th September. It was Opened by the President, Mr. J. Bullen who also chaired the opening session in which Mr. K.F. Whittle, Chairman of S.W.E.B. spoke on “The Future of Electricity Generation in the UK” with special reference made to the South West. After a short interval the programme divided between two groups. Mr. D.S. Fleet, Head of Metal Extraction Division at Warren Springs Laboratory gave a talk on “Metal Extraction R & D at Warren Springs”. The second Group was addressed by Mr. R.W. Latham of G.E.C. Electrical Projects Ltd. presented a paper on “Safe Man Riding in Mines.”
Following lunch there was again two groups. One group heard a speaker from Atlas Corporation who talked about “The Efficient Use of Compressed Air”. The other group was given a talk by Mr. R.L. Burnett, District Inspector of Mines and Quarries on the subject of “Radon: Its Impact on Mine Ventilation” Closing remarks to all delegates were given by Mr. R.H. Parker.
The second General meeting on 19th October was a joint meeting with the Minerals Engineering Society held at the ECLP Research Laboratories when Mr. J. McCormich of Chartered Consolidated presented a paper on “Potash Operations at Boulby”.
The third General Meeting on 16th November had a talk by Messrs. J.N.H. Ward and D.J. Brooks of the South Western Electricity Board on “Electricity Supply”.
On 14th December the fourth General Meeting heard a talk by Mr. D. Kendal-Carpenter who had recently been Principal of the Cable and Wireless training School at Porthcurno. His subject was “Cornwall – Birthplace of the Telecommunications Revolution” and he supported his talk with selection of photographs and examples of historic equipment.
The Fifth General Meeting on 25th January, 1984 heard Mr. J.N. Dowling of Carnon Consolidated Tin Mines, Ltd. give a talk on “Wheal Jane Operations”.
On 22nd February there was a Joint Meeting with the Minerals Engineering Society when a speaker from Amax Hemerdon Ltd. gave a talk on the Hemerdon Project.
Another Joint Meeting, this time with the Royal Geological Society of Cornwall was held on 21st March when Mr. J. Rivington of Hunting Geology and Geophysics delivered a lecture on “Information from Satellite Imagery”.
The Annual General Meeting was held on 9th May but there is no written record however the Secretary presented a report in the Newsletter covering most of the topics described above. He also noted the poor at attendance at Institute Meetings which was only averaged eighteen. It was rather better at Joint Meetings when the average was forty five. He noted that low attendances made it difficult to attract good speakers.
He also issued a statement on the financial situation for 1983. The bank balance on 1st January was £1313.98. Subscriptions amounted to £580.00. Payments for the Symposium and Dinner came to £391.50 and £273.00 respectively. Bank interest was £511.48. Secretary’s fees for 1981 and 1982 amounted to £200, Secretarial expenses came to £204 and sundry printing costs came to £85.75. The Symposium costs were £383.55 and Dinner costs were £308.70 . The balance on December 31st was £1547.90.
The William Thomas Memorial Fund held a balance of £159.90 on 1st January and with dividends and bank interest there was balance of £168.97 on 31st December.
At the completion of the formal there was a talk on the “The China Clay Industry” given by Dr. S.R. Dennison, a Director of ECLP. Ltd. He spoke about the changes that had taken place in the industry since the mid 1950s. He said that the oil crisis had resulted in a rapid re-appraisal of the efficiency of the industry. He said that this had resulted to technical improvements and, unfortunately, some redundancies but the end result was a leaner, more efficient industry better able to face the future.
Mr. L. J. Bullen served his second year as President and the programme followed the customary pattern of six General Meetings three of them joint meetings.The lecture programme was preceded by two visits. The first in July was to RNAS Culdrose and the second in September to Holmans Dry Dock at Penzance followed by visit to the Hayle Sewage Works. The Annual General Meeting was followed by a final lecture.
The first General Meeting on 17th October 1984 was given by Mr. J. H. Trounson. M.B.E. who presented a paper on “Mining Prospects in Cornwall” and the second General Meeting on 14th November had a talk on “Planning and Construction of the Hayle By-pass” by Mr. C. Stringer of Freeman Fox and Partners.
On second General Meeting on 12th December was was held jointly with the Minerals Engineering Society at the ECLP Research Laboratories, St. Austell when Mr. P. Heap of Mathew Hall, Ortech plc, delivered a paper on the “Polaris Lead-Zinc Project”.
The third General Meeting, scheduled for 16th January 1985 had to be cancelled because of bad weather. The fourth General Meeting on 16th January, 1985 was given a presentation by Mr. J.N.H. Ward and other staff from S.W.E.B. Cornwall Area on the subject of “Remote Control and Data Collection of the S.W.E.B. Distribution System in Cornwall.”
Another Joint Meeting with the Minerals Engineering Society was held on 13th February when there was a talk by Mr. C. Jones of Carnon Consolidated Tin Mines Ltd.” on “The Deepening of Clemows Shaft at Wheal Jane”.
The sixth and final General Meeting held on 20th March was another Joint Meeting, this time with the Royal Cornwall Geological Society, when Dr. J. Garnish of the Energy Technology Support Unit gave a paper on “The Latest Developments in Geothermal Energy Research’.
The Annual General Meeting was held on 24th April but no records of the proceedings or any statements on the finances have been found. The Meeting was followed by a lecture from Mr. R. Parker, CSM, on “Malaysian Tin Smelting and Mining”.
The President was Mr. E. Crowther and during the session which there were two visits before the start of the lecture programme. This consisted of six General Meetings including two jointly with the Minerals Engineering Society and one with the Royal Cornwall Geological Society as well as the AGM which was followed by a final lecture.
The first visit in July was to the South West Electricity headquarters at Pool with a talk on recent developments. The second visit in September was to Goonbarrow pit at Bugle and the Wheal Martyn China Clay Museum. Unfortunately the weather was poor for what was a well attended meeting. The party viewed primary clay production at North Goonbarow Pit Bottom and were able to inspect exposed timbered underground workings of the old Beam Mine at nearby stope face. Following lunch the party was conducted round the Wheal Martyn Museum by Mr. D.Creba, asunder member of the Wheal Kernick Geological and Mineral Society who offered to conduct geological tour in the Hensbarrow district at a later date.
The first General Meeting on 16th October 1985 was the occasion for the Presidential Address when Mr. Crowther spoke on the present state of the engineering industry and the attendant difficulties in communicating information between the various professions.
On 13th November the second General Meeting heard a talk by Mr. K. Quinby of Carrick District Council on “Operation Minecap”. This project was intended to trace, locate and secure unsafe mines hafts in the Carrick District area. He said that in sealing off these hazards to humans they had to have regard for the welfare of the subterranean bat residents.
The third General Meeting on 11th December was held jointly with the Minerals Engineering Society at the ECLP Research Laboratories when Mr. M. Proudfoot of Marine Mining Cornwall Consortium described his organisation’s operations which include skimming recent tin tailings from the sea bed and then concentrating it with the added complications of sea shells which the Secretary
On 15th January 1986 the fourth General Meeting was addressed by Mr. B. Whitehouse of Compare Holman Ltd. on the subject of “Hydraulic Drilling Systems with Reference to Production Operations” which the Secretary noted was a very informative presentation without giving any details.
The fifth General Meeting on 12th February was the second joint meeting with the Minerals Engineering Society at which Mr. B. Thomas gave a paper on “The Use of Explosives in English China Clays China Clay Division”. His presentation included a film and an exhibition of seismic instruments and demonstrated to improvements these these had made efficiency and environmental conservation.
The final General Meeting on 19th March was a joint meeting with the Royal Cornwall Geological Society when a talk was given by Mr. M. Mount, Chief Geologist of Geevor Tin Mines on the subject of “Golden Witwaterstrand”. He gave a detailed geological and structural description of this famous mining field and an interpretation of its genesis in Azoic times.
The Annual General Meeting was held on 23rd April although there is no information of the proceedings. After the completion of the formal business a talk by Mr. J. Dowling of Carnon Consolidated on “RTZ Operations and Plans in Cornwall” but due to the international tin crisis at the time this was cancelled. In its place Mr.R. Moreby and Dr. F. Allister also of Canon Consolidated Ltd. gave a talk on “Control of Exposure to Ionising Radiation in Mine Operations of Carnon Consolidated Ltd”. There are no records of the content of the talk.
Mr. E. Crowther was in the second year of his Presidency and during this busy session there were three visits before the main lecture programme which included six General Meetings and the AGM. The first visit was to the British Rail Maintenance Depot at Longrock on 26th July and it was conducted by Mr. J. Vinton, Engineering Supervisor who said that this spot concentrated on passenger train rolling stock upkeep while the spot at Laira specialised in Diesel propulsion. Mr. Vinton described the modern developments in passenger rolling stock and the wear and tare on components such as braking systems and arrester pads. He said rolling stock is inspected at every turn round at Penzance besides periodic checks and very check is recorded on computer log which is augmented by observations made by staff and passengers from as far away as John O’ Groats.
The second visit took place on the afternoon of the same day when the group moved on to Unigate Foods at St. Erth Creamery. The visit was arranged by the manager, Mr. D.R. Tilby and conducted by Mr. D.G. Hipperson the Engineering Manager assisted by two colleagues. A video film was shown describing how the factory occupied a building which was originally a china clay dry but was taken over by Primrose Dairy which became part of Unigate Foods. The party was shown the process starting with the import of farm milk, its spa ratio by Alfa Laval machines into cream and skimmed products. The party was them treated to refreshment in the Company’s Club and left with a pot of clotted cream each.
The final visit of 10th September was to Teagle Machinery at Blackwater. This old established family business changed its trams of reference after the second world war to become research and development and manufacturing and exporter of farm machinery to all parts of the world as far afield as Australia. Mr. Teagle took the party on a tour of the workshops including steel fabrication from raw materials into component parts machined mainly on automatic jigs and assembly into the final products ready for painting and corrosion proofing. The visit concluded with a discussion during which photographs were shown of Teagle inventions such as bicycle petrol propulsion in the early days to a hydraulic controlled hedge trimmer.
The lecture session included five General Meetings including two with the Minerals Engineering Society and one with the Royal Cornwall Geological Society, a Symposium and the Annual General Meeting followed by talk.
At the first General Meeting on 24th September 1986 the President gave details of the meeting programme and heard a paper by Dr. I. Blair, Scientific Advisor, UK NIREX Ltd on “The Management and Disposal of Radioactive Waste”. He gave an account of the the radioactive materials produced in Britain’s Atomic Energy Industry from the Magnox reactors. Some of this was recycled for further use in the pile and the remainder separated into fractions containing high, medium and low intensity. The first after suitable resting period was encapsulated in special steel containers and stored in dry underground chambers in impervious rock or disused salt mines. He noted that the fissured water bearing granite in Cornwall would make it unsuitable for such an examination.
The second General Meeting on 2nd October was a symposium on “The Development and Operation of Tara Mine”. The ore deposits were found by a Canadian Company in a survey carried out in 1962. This mine the largest zinc-lead mine in Europe in County Neath is in the Irish Republic near the historically famous Tara Hill, started production in June 1977. The Symposium was opened by the Institute Chairman Mr. E. Crowther and the introduction to the subject was made by Mr. D.J. Libby and papers covering four topics were presented by employees on the Company. Including the speakers the attendance was 58.
The General Meeting on 12th November was held jointly with the Minerals Engineering Society and took the form of an open forum attended by about 100 members and guests on “The Future for Cornish Tin”. It was chaired by the President and the panel members were Mr. B. Calver, Managing Director of Carnon Consolidated, Mr. K. Gilbert, Manager of Geevor Mines, Mr. G. Pengally, Consulting Mining Engineering. A fourth panel member, Dr. P. Hackett, Principal of CSM, was unable to attend.
The three panel members each gave short talks on the ventures of their respective companies. Mr. Calver said they Carnon was pushing ahead with modernisation at South Crofty and Wheal Jane with financial aid from the Government while Mr. Gilbert said that had not been so fortunate and austere working conditions remained at Geevor whole the Redmoor exploration project had been closed for similar reasons. In the general discussion the consensus seemed to be that if the operating mines continued to modernise their systems for the next four years the world price of tin would ameliorate and once more production costs and income would become compatible. However the envelopment of substitutes for tin and the discovery of more easily exploited Cassiterite deposits abroad meant the the long term future led to the inevitable expectation that the Cornish Tine industry was heading for extinction in the forceable future.
The third General Meeting scheduled for 14th January 1987 was cancelled because of bad weather.
The fourth General Meeting on 11th February was held jointly with the Minerals Engineering Society to hear a lecture delivered at the ECLP Laboratories by Mr. Rawson of Eriez Magnetics Ltd. on “Magnetic Separation”. He covered the basic principles and recent recent developments applied to mineral dressing and in particular the removal of Pyrite from coal supplied by the National Coal Board to the Central Electricity Generating Board. This is aimed at reducing the problems of acid rain caused by power station exhausts.
The fifth General Meeting was also a Joint meeting, this time with the Royal Cornwall Geological Society when the president introduced Miss. J. Holl who presented a paper on “Mineralisation at Wheal Jane, Implications in Exploration and Future Processing”. The lecture dealt with a remote period 280 million years ago when, after the Cornish granite batholiths were created the overlying slate was tended and infilled to form the familiar lode systems. She described in detail the accompanying physical and chemical processes involved which resulted in the fractionating of the various minerals with their respective textures and compositions with special reference to Wheal Jane. The talk was pertinent to the mining geologist but also the thermodynamicist engaged in the pyrotechnic developments of chemical engineering and extraction metallurgy. It was noted that only fourteen members of the Institute were present but visitors raised the audience to over 100.
The President for this session was Mr. H.R. Falcon-Steward who oversaw a programme of three visits before the start of the programme of six General Meetings which included three joint meetings.
The first visit on 21st June was to the Calestick railway track of the Perrnaporth and District Model Engineering Society. The members who attended enjoyed amongst other things riding round the track on dollies pulled three and a half inch and five inch gauge steam locomotives.
The second summer visit was to the water treatment plant at Stithians Dam. The visitors were shown round the dam itself then a tour of the operations including reagent addition, flocculation and filtration and the automated control room. The visit was organised by Mr. J.P. Lewis, Operations Manager of the Fal district of the South West Water Authority.
The final visit was an evening event to the Charleston Engineering Foundry where a large number of staff were on hand to show small groups through the pattern making shop, the mould making shop, foundry and furnace area through the machine shop finishing at the galvanising plant. The evening was rounded off with splendid buffet and a lively discussion.
The President delivered his Presidential Address at the first General Meeting on 14th October when he presented a paper on “Marble” in which he described the geological formation of marble and accompanying minerals before describing its mining, treatment and use in dimension stone in blocks up to ten metres size for building and decorative purpose down to pigments down less than 0.001mm. He dwelt particularly on the use of agitated media mills with feed size of less than 50 microns and product size of less than 1 micron used in paper coating.
The second General Meeting on 18th November heard the talk by Mr. J. Brock which had been postponed in January because of bad weather. His subject was “the History of Cornish Tin Mining”. He dealt initially with the emergence of the use of tin during the Bronze age and its subsequent arrival of mining in Cornwall and the following development of the industry. He summed up the geology of the tin producing areas and their output over the centuries coupled with the supporting industries such as railways, smelters, explosives and the emergence of banking for the industry. He then spoke about some of the people involved form niners to magnates. He ended with the comment that the Cornish mining industry has somehow overcome adversity in the past and expressed the hope that it would do so in the future.
The third General Meeting held jointly with the Minerals Engineering Society on 9th December heard Mr. A. Wells the Mill Superintendent at Wheal Jane giving a talk on “The Ultimate Recovery”. He outlined the maximum and minimum levels of premium and penalty elements applied to the smelters and gave his definition of “economic recovery”. He showed a flow sheet of the Wheal Jane concentrator outlining the operation of each section and described ways of improving economic recovery within itself and with respect to preceding and succeeding stages. He conclude with an interesting description of the installation of column flotation and innovative technique to capable of producing concentrates of up to 40% tin without seriously affecting recovery.
The fourth General Meeting on 20th January 1988 heard a talk by Mr. D. Reynolds of the Perranporth and District Model Engineering Society which had hosted visit by the Institute in the previous summer. He said that there was a very wide cross section of people who were model engineers and their facilities ranged from simple table with a vice and files to a fully equipped workshop. He pointed out that anyone taking it up was well advised to join a club or society to gain knowledge covering a wide range of interests from engines both story and mobile to aeroplanes and stationary and working ships. He illustrated his talk with slides and models.
The fifth General Meeting on 17th February was a joint meeting with the Minerals Engineering Society and it was addressed by Mr. S. Gutley, Mine Superintendent, South Crofty on “Mining Development at South Crofty”. He commenced by giving a potted history of South Crofty in order to set the scene for the latest developments. He then described the development of Cook’s Kitchen shaft which was ro be used to accommodate both man riding and hoisting. Robinson’s was considered too costly to refurbish and was to be closed. However, as mining lw required two egresses a decline was being driven from Tuckingmill. A sub incline was at the time of the lecture was already down to the 455 fathom level and advancing at 9 to 12 metres per week.
Mr Gatley described the installation of three new pumps each capable of pumping 1000 gallons per minute. This was so that all the day’s water make up of up to 2.1 gallons could be pumped at night to take advantage of cheaper night time electricity rates. He also described changes in changes to stoping practices which had increased advance rates from two to three feet per man shift. He finished on the subject of ventilation saying it would double from 90,000 cfm to 180,000 cfm when the East Pool shaft was unblocked and new fans would increase this to 250,000 cfm when new fans were installed.
He concluded by saying that the total length of the mine from east to west was 3km and demonstrated ore reserves were 2.4 million tonnes at 1.8% Sn and 4.5 million tonnes at 1.5% Sn.
The sixth General Meeting was another joint meeting, this time with the Royal Cornwall Geological Society. It was held at the EEC research Laboratories at St. Austell on 16th march when Messrs. J.H. Howe and C. Varcoe of ECC International spoke on “The Planning and Reserve Evaluation of Open Pit China Clay Mines: An Overview and Recent Developments.” The paper dealt with the development of a data logging system and commuter model that could be used to overcome the many problems that could be encountered in mining and blending 3 million tonnes of raw material from as many as 18 different pits to yield a wide range of products of consistent qualities. A team of four was used to record the survey data and operate the computer where it was combined with the geological and chemical data to provide the necessary information for selective mining and blending and also controls over- and under-mining by projecting borehole influence .
The Annual General Meeting was held on 20th April.when the Secretary presented his report which covered the meetings programme described above. He noted with regret the death of Mr. J.H. Trounson MBE, who had been the Institute’s Honorary Treasurer for many years and who had died 5th July 1987. The meeting stood for two minutes as a mark of respect. The Secretary also noted that a Memorial Fund had been set up to provide a prize at the Camborne School of Mines.
He also advised that membership was 126 and attendance at meetings ranged from 13 to 42. The Treasurer presented the Balance Sheet for 1987. It showed that the bank balance on 1st January was £1879.64, subscriptions came to £456.00, interest provided £133.39, dinner tickets provided £222.75. Other minor items came to £39.00 giving at total income of £851.14. The Secretary’s expenses amounted to £146.97, expenses connected with the late Mr. Trounson were £69.50, the dinner cost was £220.10 and there was £10.00 for an affiliation fee giving a total of £446.57. This gave balance on 31st December 1987 of £2284.21.
The William Thomas Memorial Fund increased from £203.47 to £213.60 as a result of interest and dividends. No prize had been awarded.
The Cornwall Industrial trust investment had increased by £910 to £13,050 representing a yield of 6.97%.
Mr. H. R. Falcon-Steward was due to carry out the second year of his two year term of office but he resigned before taking up the post which was taken up by Mr. K. J. Menadue. Mr. E. Crowther, Secretary and Mr. T. Reeve, Treasurer continued in those posts.
The programme included three industrial visits, two of them in the morning and afternoon of same day. The morning visit was to the home of Mr. D.A. Pearce of the, Research and Development Laboratories, E.C.C. The visit had no connection with his work but was concerned with his hobby which was the collection and refurbishment of engines and machinery. He owned a very large collection, started by his late father and himself, of stationary and mobile engines of all kinds diesel, paraffin and petrol dating from1899 through the early years of the 20th century. He also showed the collection of vintage garden and farm equipment including a 1927 Lanz tractor, probably the oldest of its type in the Britain. The visit closed with a showing of a film made by G. Wall’s film on waterwheels followed by a buffet lunch prepared by Mr. Pearce’s mother.
The afternoon visit was to Delabole slate quarry where the manager, Mr. G. Hamilton welcomed the small party. He recounted the recent history of the quarry where slate had been mined for over 400 years and said it covered 40 acres and was some 500 – 600 feet deep. A few of the visitors ventured to the bottom descending via the peripherally descending haul road to the workings at the bottom where they saw the great beds of slate being machined with endless wire saw blades into blocks 6m log and 5m high by 3m wide and weighing 270 to 300 tonnes. The visit concluded at the processing and dressing shops on the surface where the slate was reduced by sawing and cleaving to the required sizes and shapes.
The third visit was to the early in September to the British Telecom telephone exchange in Truro which covers the we tern half of Cornwall involving about 150,000 lines. It was explained that calls were received on a “queuing” system each reception point being served by computer terminal and the target time for answering call was 25 seconds. The computer was actually in Exeter and there were 46 line-men for the area. The group then saw the local area STD Group Switching System which is electro-mechanical (Strowger) system before going on to the Mk 4 electronic switching system and the Pulse Code Modulation (PCM) system which was in the process of being developed into System X. The visitors finally saw the switchboard area which has two telephone consoles each about 20 feet long with about a dozen operators. This handled all calls to the operator and 999 calls for the emergency services. It was explained that the unit handled about 250 emergency calls a day and were three emergency calls while the visitors were there.
The first General Meeting was held on 12th October when Mr. G. Pritchard gave a talk on “Alternative Energy in the South West” He opened by saying he would concentrate on three renewable sources of energy – wind, small scale hydro and waste. He said that the first wind generator had been installed at Redruth many years before and the most recent one was the Cornwall energy Project near Helston. The total funding for that project was £319,000 shared between Cornwall County Council, the Department of Energy, EEC, Shell and the local Council. He said that 341 possible sites for wind power had been identified with a total capacity of 560 MW.
He then went on to say that there were more than 1500 potential small scale hydro sites in Cornwall which might provide 31 MW of power to houses and small industries. He then spoke about electricity from waste and said that a site in Plymouth took waste from Exeter and Torbay as well as Plymouth but he did not give figures for the electricity generated. He said that in Cornwall there were 450,00 cows which produced as much sludge as 95 million people and it generating potential was 64 MW. Finally he said there was a certain potential to use old mine workings for pumped storage schemes and the potential was about 100 MW. He conclude by saying that the total potential for the south-west’s about 727 MW.
The second General Meeting on 16th November was given a talk by Mr. P. Haynes, area Chief Engineer, Balfour Beatty on the subject of “Construction of the Saltash Tunnel.”
He said that sine the A30 was becoming the main route into Cornwall the road infrastructure round Saltash was till too congested and the tunnel was intended to ease this problem. Much of the work had to be carried out in bad ground and therefore there were several different methods needed to overcome these problems. The bad ground needed to have arch ribs installed while the more competent ground could be rock bolted and shot-creted and permeable membranes had to be built into the tunnel to carry away seepage water because the concrete lining was not designed to withstand the water pressure. The centre of the cross section has a 14m span and only 16m ground cover to the properties above. Cross sectionally it was one of the largest tunnels in the UK being only four inches short of the four-lane Mersey tunnel. 35,000m cu metres of rock were removed much of it being used for the fill required for the approach road work.
The talk was illustrated with slides, charts and overhead projector work.
The third General Meeting on 7th December was held jointly with the Minerals Engineering Society when Mr. R Mozley of Richard Mozley Ltd. spoke of “Gravity Concentration over Thirty Years – One Man’s Contribution”. He showed a video giving the history of his involvement with gravity concentration during more than thirty years. His latest invention had been the Multi-G Separator which was an enhanced gravity concentrator for the separation of solids in liquid suspension and able to operate on very fine particle sizes. He said the device had capacity of up to 250 kg per hour and would be able to separate particles in the range 250 down to 1 micron of slurry of 10% to 50% by weight.
On the 18th of January 1989 Mr. A.W. Brooks of CSM spoke on “King Edward Mine: 1897 – 1923”. He told of the early history of the School of Mines and the realisation that it would be advantageous to have a small mine with no pumping to keep costs done where practical instruction could be given.
Great Condurrow mine had been driven southward to South Condurrow but this had become uneconomic and the abandoned eastern section was sold to the School for the sum of £325 which included the surface buildings and the existing steam whim.
The mine was in such poor conditions that much rebuilding and re-timbering had to be carried out as well as the building of a new Survey Office and headframe and a new Holman 18” x 12” compressor. A treatment plant also had to be designed and built .
During the early 1900s there was steady decline in student numbers so 1914 when WW1 broke out the mine was put on a care and maintenance basis.
There was a slight revival after the war but the tin crash of the 1920s saw the end of operations at Wheal Granville which stopped pumping and the mine was left to flood. Naturally King Edward soon followed and by 1921 all levels had ben lost. However small part of the Great Condurrow Mine next door was still accessible so a new underground facility for the school was developed there wand it was still in use at the time of the Mr. Brooks’ talk.
The fifth General Meeting on 15th February was a joint meeting with the Minerals Engineering Society and was given a talk by Dr. I Wells of Boxmag Rapid on the subject of “Magnetic Separation”. He started by defining the different types of magnet ranging from the weakest, permanent alloy magnets then much stronger ceramic ones and then the very much stronger rare earth alloys. Finally there were the electro magnets which could be much the strongest. He then displayed a table of minerals and the magnetic flux required to pick them up. He gave examples of four main types of separation. Low intensity dry which was used in arid or semi arid zones for the separation of magnetite. Low intensity wet separation was also used for separating magnetite and some ferrosilicon. High intensity dry separation use for the concentration of paramagnetic materials such as ilmenite, garnet and wolframite and well as the separation of siderite and cassiterite. Finally high intensity wet separation was also used for the separation of paramagnetic materials such as ilmenite and wolframite.
He concluded by giving an example of dumps of a million tonnes in Peru being treated by a mixture of wet magnetic pre-concentration follows by shaking tables, flotation and high intensity dry separation. The mineralisation of the dumps was quartz, pyrite, siderite, chalcopyrite, magnetite and wolframite. He conclude with a demonstration of small, powerful magnets.
On 15th March the sixth General Meeting was held jointly with the Royal Geological Society of Cornwall to hear a talk by Dr. S.T. Hall of Camborne School of Mines on “Industrial Minerals in the UK – An Overview of Their Occurrence, Treatment and Uses”. He started by saying it would, of necessity, be a whistle-stop tour and continued by saying that although it was a much neglected area it was becoming more important. He defined an industrial mineral as any raw material not used as a source of metal. Non-metallic minerals tended to be produced from “high value” sources where the concentration of the material was high and the cost of the finished product was low. As examples he quoted coal and china clay as examples. Other minerals of which more than one million tonnes were extracted were limestone, dolomite, igneous rock, gypsum and, depending on the severity of the winter, rock salt. Closely followed but under one million tonnes were Fireclay, ballclay, potash , iron ore, fuller’s earth, slate and barytes.
He spoke about some minerals which were produced only or mainly in specific area. China Clay was well known and potash, used mainly for fertiliser production all came from Cleveland Potash in north-east England. There were two main producers of fluorspar, one in Derbyshire and one in County Durham but production had been cut-back because in line with similar cuts in the steel industry. Celestite (SrSo4) occurs near Bristol and was used mainly in pyrotechnics. Talc was only produced in UK in the far north of Shetland which produced about 2000 tons per year which was used mainly in the paper, plastics and paint industries.
The Annual General Meeting on 10th April when it was reported that the two Vice-Presidents had resigned and this resulted in several changes to the Council. Mr. F.P. Rees was elected to be President for the 1989-1990 session to take over at the Biennial Dinner and it was agreed that the Council would appoint two Vice-Presidents at the earliest opportunity.
The Balance sheet for 1988 was presented and showed that the bank balance on 1st January was £2284.21. Income from subscription was £451.00, bank interest amounted to £130.12 and there was a donation of £500 from the estate of Mrs.Higley. The Secretary’s expenses came to £171.02, there was an affiliation fee of £10 and two year’s honoraria amounted to £200. Total expenditure was therefore £381.02. The resulting year end balance on 31st December was therefore £2984.31.
The William Thomas Memorial Fund rose from £213,60 to £222.03 as a result of interest and dividends. Since it was set up the J.H. Trounson Memorial Fund had received donations of £1963.57 and with bank interest of £121.77 had closing balance of £2085.34.
There was also a report on the finances of the Cornwall Industrial Trust for the year 1988. It showed the value of the Trust’s investments on 31st December was £6697.58. The income during the year had amounted to £984.66 and grants of £1000 had been made to students.
At the close of the formal business the President invited Mr. L.J. Bullen , Chairman of the Cornish Mining Development Association to give his illustrated talk on “Historic Cornish Mining Scenes.”1989/1990
The Biennial Dinner was held in June at the Basset Count House, Carnkie, when the new President, Mr. F.P. Rees formally took post and thanked the retiring President for his work.
As was now customary the session started with three visits the first two of which took place made July 15th In the morning a small party visited Geevor Mine and saw a video of the operation viewed the plant and a collection of mineral specimens and various historic artefacts including a scale model of the old processing mill that was awaiting restoration.
In the afternoon only five members joined a visit to the Rosevale Mine at Zennor where they were conducted round the underground workings by Mr. M. Shipp. This small mine was operated by a small band of enthusiasts who operate it to keep the old hand mining skills alive.
The second visit on 13th September was made to RAF Portreath which was an old WW2 fighter station but at the time of the visit was a radar station acting as satellite station for the UK Air Defence tracking network. There was back-to-back radar antenna which resulted in two target returns for every four second sweep. There was also a “nodding” height finding radar built railway apprentices in Newcastle-upon-Tyne. The visitors had an explanation of the operation of the system and how it was used to identify all air traffic in the to segregate friendly and potentially hostile aircraft. The visit concluded at the maintenance workshops which the Secretary reported to be the “epitome” of good engineering practice”.
The First General Meeting on 11th October was the occasion for Mr. F.P. Rees to deliver his Presidential Address on “Energy in the Pipeline – The Design and Construction of a Sub-Sea Pipeline” as his subject. He started by pointing out that the energy in Cornwall was all brought over the Tamar. The energy sources were Oil:- 40%, Gas:- 20%, Electricity:-20%, Coal:- 15%, Others:- 5%. Most of the oil was from the North Sea and it was pumped ashore by submarine pipelines. The design and construction costs could be as high as £1 million per mile. The necessary sea bottom survey had to be carried out early in the design phase and all data had to be referenced to an accuracy of of 3 -5 metres.
For the construction phase a semi-submersible pie laying barge was use to weld 40ft sections of steel pipe into a continuous string on the seabed under tension.
The second General Meeting held on 15th November was to have been given by by speakers from Mott Macdonald on “The Construction of the Saltash Bypass” but unfortunately they did not turn up. The Secretary noted that this saved an embarrassing since only half a dozen came to hear the talk.
The third General Meeting held jointly with the Minerals Engineering Society was better attended with an audience of 18. The meeting had a talk by Mr. M.H. Prior of Hosokawa Micron UK.k on “Air Classification and the Ecoplex High Pressure Rolling Mill”. However despite the title his talk concentrated on the High Pressure Roller Mill and he said the high compression roller mill was based on original designs for conventional roller mills with the added advantage of being able to apply high pressure. This pressure was applied by a hydraulic ram and the pressure on the ram was 80 – 200 bar which allowed transmission to the grinding bed of up to 6000 bar. That allowed an increase of up to 35% throughout in a ball milling circuit if it was installed before the ball mill.
The Secretary said that Mr. Prior went through the abstruse mathematics relating mill parameters to throughput and projected many graphs showing a comparison of parameters and how they were use to select a mill. He said that the only disadvantage was the high capital cost compared to ball mills. In addition those mills could handle a large variety of materials.
The fourth General Meeting on 17th January 1990 had lecture by Dr. M. Anderson of Vertical Axis Wind Turbines. He started by stating the wind energy passing through 1square metre per year in various regions of the country but unfortunately he did not give figures for the West Country. He spoke of the history of windmills over the years from the well known “Dutch” type to modern horizontal axis machines. He then described the less conventional vertical axis machines then capable of outputs of up to 2 MWh. He described the steps that had been needed to overcome considerable vibration problems. He said the biggest wind generator at that time was the Darius design, theoretically able to produce up to 4MWh but at that time had only produced 2MWh. He said the principal advantages of the Vertical Axis Wind Turbine were that it was omnidirectional, non-reversing, could be designed for high or low level plant, had high rotor inertia and was much quieter. He said that the then current deigns had blade speeds of about 50 rpm working through gearing to produce generator speed of 1500 rpm. The design life of the turbines was 15 years.
The talk had obviously created considerable to the local community since the attendance was 94 although only 23 of them were members.
The fifth General Meting on 14th February was another held jointly with the Minerals Engineering Society and it heard a talk by Mr. M. Hallewell of Carnon Consolidated whose subject was “Recovery of Tantalum and Spodumene in Canada”. He said the paper arose from a commission to Carnon Consolidated to investigate the operation of the TANCO concentrator in Manitoba, Canada and to improve the recovery of the plant. The deposit, of tin, had been discovered by a Cornishman, J. Nutt in 1929. It was released that there was also lithium there but the deposit was not worked until the 1950s when spasmodic work went on until the late 1980s. The concentrate contains 35 – 38% of Ta2O5, 14 – 18% of SnO2, 3 -5% of Nb2O5 and 2 – 5% of TiO2. He said that 60% of the concentrate was shipped to Germany and 49% to the USA. Tantalum was used for manufacturing pins for securing artificial joint in the human body and the manufacturing of tantalum carbide for cutting tools. The main world producer was Thai Tin Mines which produced 1million pound weight followed by Greenbush in Australia and TANCO with 25,000 and 240,000 pound respectively and African Tin Mines producing 200,000 pounds. The major minerals produced at TANCO were spodumene, sodium, amblygonite, wodgonite, microlite, pollucite, lepidolite and potassium feldspar.
In 1988 six million dollars had been nested in extending the plant, for the recovery of Tantallum and production capacity was 670 tons per day (tpd). this limitation being imposed by blinding screens and overloaded shaking tables. The screening problems were overcome by changing from punched hole to slotted screens which improved throughput from 26 tad to 31 tpd. Modification to the spiral circuit produced an improvement in recovery from 62% to 65%. It was realised that the regrind mill in the fines circuit so this was taken out of circuit and further improvement in recovery from 65% to 67% was achieved. Finally the Bartles-Mozley concentrator was replaced by 2” Mozley cyclones with the underflow going to cross-belt separators. This pushed recovery up to 70%, the total improvement of 15% resultd in an increase in revenue of 2 million dollars.
The sixth General Meeting on 14th March was a joint meeting with the Royal Geological Society of Cornwall to hear lecture with the intriguing title of “Cabinet Making and the North Penine Orefield” given by Professor W.R. Dearman. He started by saying that in the late 17th and early 18th centuries a number of people scattered round the metalliferous mining areas were attempting to understand and depict what was “going on” underground in the geological sense. They included Pryce on Cornwall and White-Watson in Derbyshire who was a craftsman in marble who collected minerals and fossils. Rather than draw he made his diagrams of the underground stratification as a mosaic in which the strata were made from small tessera of the actual mineral, such as limestone, granite and so on.
These model makers knew they were dealing with fault systems but did not fully understand them. At some stage some unknown person made some excellent wooden models of various fault systems which were later found in the library of the Geological society in London. At first they were not understood but after some time it was realised that the wooden “strata” could be slide along each other to represent various types of underground faulting. These models had to fit together very accurately so the craftsmanship had to be over very hight order. In the North Pennine Orefield the orientation of the ore deposits was very well known and the models could be adjusted to represent all the faulting in this system. One of the most important figures in charting the history of the North Pennine Orefield was Thomas Sopwith, born in 1803, who was a member of family of cabinet makers although it seems that he was not aware of the earlier work on wooden models and he made three dimensional wooden models using different coloured woods to represent the strata. He published a description of his models which were 4” square and 2” to 4” thick. There were twelve and he sold them as sets of twelve in “book boxes” as teaching aids to demonstrate what was “going on” underground. He also made much larger models which could be de-mounted to examine the strata and mark in mine workings.
The Secretary later noted that it had taken Professor Dearman and his colleagues a considerable amount of time to establish hat the models were made in the Sopwith family workshop where the necessary woodworking skills were available.
The Annual General Meeting was held on 18th April and there was no report of the proceedings or any discussion that took place. One Council Member had resigned and four were due to retire. In elections for the 1990/91 session. Mr. F. P. Rees would be President for his second year and there had been no nominations except for the four retiring Members who were re-elected for the new session.
The balance sheet for 1989 show that on 1st January the bank balance had been £2,984.31 and Subscriptions, including arrears provided £613. Tickets for the biennial dinner brought in £207, sales the small sum of £5 and interest on deposit accounts £191.00. The total come was therefore £1016.50. On the expenditure side the Secretary’s expenses were £73.11, printing £86.55, a donation of £510.00 was made to the Cornwall Industrial Trust. This was because the sum of £500 from the estate of the late Mrs. Higley had been credited to the CIE General Acount in 1998. The usual Affiliation Fee of £10 was paid , competition awards amounted to £40.75 and the dinner costs were £214.80 which represented a loss of £7.80. Total expenditure was £935.21 which resulted in a bank balance of £3065.60 on 31st December. It was noted that £200 had been sent from the the Trounson Memorial Fund to the Principal of CSM for the award to a student as previously agreed. it was also noted that the drive to collect subscription arrears hd been successful sine the income from that source had been some £150 higher than usual.
A statement on the Cornwall Industrial trust stated that the current value of its investments was £13348, an income of £1135, representing an average yield of 8.5%.
Following the end of formal business Mr. B. Earl was invited to give a talk on “Development and History of the Explosives Industry in the South West with particular reference to Cornwall”.
The talk was well received and it brought to an end the 1989/1990 lecture season.