MINING INDUSTRY

Manawatu Standard, Volume LIII, Issue 51, 27 January 1933, Page 6

MINING INDUSTRY

THE CHEMIST’S PART. VALUE OF RESEARCH. “With lower costs now prevaient and with a premium on gold, * he j™ 1 ", 1 ” 8 industry has deceived fresh The future may lie in the tieatmc low grade ores, and the trained chemist will be called in again to assist in. the industry, which lias considerably n ,, fited by the application of chemistry, stated Mr W. Donovan M.Sc., F.1.G., Dominion Analyst, in his presidentia address at the annual meeting in raimerston sorth last evening of the JNew Zealand section of the Institute or Chemistry of Great Britain and Ai eland. “One can but wish, he added, “that other primary industries in New Zealand of greater importance and value than gold mining would adopt the same favourable attitude as the mining industry to technical progress and scientifically guided research. The results, I am convinced, would be equally beneficial.” BENEFITS IN PAST.

“That chemistry has played an important part in the development of the mining industry in New Zealand is due mainly to two things.—*(l) The recognition of the older generation of mining men that the processes they employed were often inefficient and were callable of improvement, and their eagerness to try other processes, even though unproved on a working scale. (2) The establishment in 1886 of schools of mines in mining centres to give even . the rank and file of the workers mining and metallurgical knowledge. Credit must be given to Hon. W. J. M. Larnach, then Minister of Mines, for 'this step. The enthusiasm with which a preliminary series of lectures was given in the various gold fields by Professor J. G. Black and a staff of itinerant instructors can scarcely be described. The knowledge imparted was appreciated and widely used.

“The training in practical chemistry given at some of the schools of mines thirty years ago was in some respects up to and beyond the then University standard. The schools provided men trained to control, adapt and modify, if necessary, recognised metallurgical processes in the treatment of New Zealand ores. Gold mining steadily progressed until in 1906 the export of gold exceeded £2,000,000 in value. After that year it declined, and for various reasons is now but little more than a fourth of this figure, but the industry has, as stated, received a fresh stimulus on account of prevailing conditions.

TREATMENT OF COAL. “Mining in New Zealand is confined practically to two branches —gold and coal. Some 2,500,000 tons of coal are mined each year. The chemist plays little part in coal winning operations. He examines the mine air occasionally for the presence of explosive and other dangerous gases. He determines the percentage of fine inert matter in the dust on the roadways, which must exceed a definite figure so that minor explosions of gas at a working face will not be transmitted by the dust throughout the whole mine. He analyses coal from the various seams for mixed carbon, volatile hydro-carbons, water and ash, and determines calorific value. This indicates their range of usefulness and governs their sale. Having carried out these various operations, the work of the chemist relative to the winning and marketing of coal at the present time ceases. “In the past some work was done on the relative inflammabilities of New Zealand coals, which proved of assistance when safe-working measures were framed. Various investigations have dealt with the suitability of single coals and of blends for gas making, resulting in a. large market being opened up for the bituminous coal in the gas industry. The possibility of the use of sub-bitumiuous coals for the manufacture of producer gas was demonstrated by workers 'at Canterbury College, but this field proved limited in scope. A study of low temperature carbonisation of sub-bitumm-ous coal laid the foundation for the establishment of the carbonisation works at Rotowaro, near Huntly. It is hoped that a recently completed investigation on briquetting of slack coal will result in the establishment of suitable plants in more than one “The industry has now, for financial reasons, withdrawn its support from research. Perhaps the chief and only service which the chemist can ren er the industry in New Zealand at the present time is to follow closely the progress of research elsewhere, and interpret the results in the light of his knowledge of New Zealand coals and New Zealand conditions. GOLD AND MERCURY.

“Gold mining at the present has an output only one quarter of the value of coal, being £519,000 for the year 1930. It was four times this in 1906. The chemist’s part in the industry is first to assay samples from working faces in the mine and determine the value of the ore in situ, so that worthless ore may be left in the mine, and only profitable ore broken out for treatment. Next by routine tests he exercises a certain amount of control over extraction processes. Again, he may be required to modify any specific method of treatment, or even to devise and try out new methods in special cases. “Metals other than gold and silver are not mined extensively in New Zealand. With regard to mercury, a solvent process for the recovery of mercury in cinnabar was investigated at the Dominion Laboratory in 1920, also the application of oil flotation to cinnabar ores demonstrated. The possibilities of flocculation, followed by. oil flotation, would be worth considering in connection with the treatment of the mercury deposits at Kaikohe, which are in very wet clay and which have not proved amenable to the usual furnace treatment. Work having relation to theories of ore deposition has been carried out from time to time.”