A Revolution in Rand Mining

Waihi Daily Telegraph, Volume IV, Issue 1158, 30 November 1904, Page 3

A Revolution in Rand Mining

UtND metallurgists have linn excited of lain by the publication of some reinnrkabl"" rosults obtained with tube niillsi by two of tho Iknd gold mines, Tube mills, which arc also known as grit mills nn d lli.mills, have been in use in Weeie. Australia and America for some yen but are quite new to the liand, • ■ only installed at present at tlio New Go and Glon Deep properties. Their oxpei inienuil working Ima, howovcr, been so successful shnii it is confidently believed in many quarters that their imrndncii,. • marks tho most important advance in tlio gold mining industry of tho llnnd since the adoption of tbo cyanide process, Although, as rioted abovo, tho tube mill has bom in use abroad for years it has roin lined for tho Hand engineers to discover a special use for it by which tnoro gold is recovered from the oro than by any other process and in less time, and more economically, Tho mill nt tho Glen Deep, which was set to work on June 15 last, was obtained from the Allis-Chnlmers Company, and was designed to deal with 50 tuns of cOiU'so sands, It consists of an iron cylinder 22 feet long, and ot 5 feet diameter, with hollow trur.nions at each end, through which tho pulp to be ground passes in at ono ond and out nt the other. Trim nil ins rest on solid barings and tho cylinder is revolved by a pullv nt a speed of 88 revolutions per minute.' The cylinder is li«ed with chilled steel, and inside is plncod sevon tons of hardest flint pebblef, about tho size of a tennis bull, and tho rounder tho better. The grinding action is performed by the rolling of the pebbles wbon tho cylinder is revolved, and is s'railar to the' altritive action resulting from waves constantly moving pebbles on tho ( soa shore,