TIN-DREDGING IN MALAYA

Evening Post, Volume CIX, Issue 149, 27 June 1925, Page 16

TIN-DREDGING IN MALAYA

SUCTION CUTTER PLANTS BEING USED.

During the last year or so a new type of a dredging plant has been introduced by Australians for the winning of tin, says tho. Melbourne"*',' Argus." This is known as the suction-cutter dredge. The plants. are really a combination of the gravel pump, so largely ■used for tinmining in the East, and the bucket dredge, excepting that the wash, instead of being lifted by buckets, is loosened and made free, by a rotary cutter head, which may be likened to the propeller of a steamer, with strong cutting blades and teeth attached.- .The tin wash is then drawn on board the pqntoori by suction and concentrated by the usual methods. ■'.■..

Like the bucket dredge, the suction cutter-has had many difficulties to overcome, arid as a result, of irritating delays during the pioneering stages, disappointment: was expressed -in some quarters, both in Australia, and in the East, regarding: tho prospect for the suction-cutter, but > Mr. Rex Thompson (Castlemaiue),, who lias just returned from _ the ; East.' after investigating the working of the ■ dredges, expresses, confidence that tho suction-cutter -will be a complete success, and will do all that has been claimed regal-ding it, in the very near future. He contends that the suction-cutter willhandle'. classes ;of material that the bucket type of plant could not touch, -in 'addition to obtaining a. large recovery from ground having a very rough or '-pinnacly 11 bottom. Mr: Thompson said that when he went to the East six months ago the position' was not too good,;but that to-day there was general confidence in the Federated Malay ■ States.'- regarding the success of the suction-cutter- dredge. . He thought tho use of classifiers and jigs for the recovery of the tin concentrates would be a great factor in respect to the future o£ the suction-cutter. This would -replace the '-.present "system -of streaming down in slunco boxes. The jigging system had been'adopted-on the Nai Hoot Juita. dredge recently completed,' and was also being adopted on the Kuchai, Kampar River, arid Huey Yot dredges now being built. .. Seven-. siictidn-cutters have been completed jn the: East', for. the following companies :—Lampeh, Tongkah Compound, Nai Hoot::Juita, -. ■ Kamunting, Kinta, and Kepong, each having an es-. timated capacity of 100,000 cubic yards a month; and "the dredge, at Petaling, which has been working about two ye,axs with a monthly capacity of 150,000 cubic yards. The plant working at Kinta, near Ipbh, which was a ■ sister dredge tothat'built for the Tongkah Compound Co., had already attained a. monthly yardage of 95,000 yards, while "'for March 87,000 yards "were handled from ground having an. average* depth of 60 feet, and. costs were down to under 10 cents a yard. "The ground being handled by the Tongkah Compound dredge is niore abrasive than was anticipated., but Mr. Thompson says this is a matter .that can easily be,overcome.' The wash is on soft bottom, and contains no large timber. He classes it as a fine dredging property, and is confident that, the stipulated monthly yardage of upwards of 80,000 yards will be attained within a couple of months. Costs' should then be under 3d a cubic, yard, The Lampeh (Siam) Company's dredge, he stated, was in very, difficult ground, with heavy timber lying' at the bottom of the wash, and under tho conditionsUie did. not think J* Q n plant would deal with more th ah 75,000 cubic yards a month. The Huey Yot cutter, dredge .now .being; built .had aiv estimated monthly -.capacity of 130,----000 cubic yards, and the Kampar. River and Ruchi plants 140,000 cubic yards. "Mr. Thompson regards the tin-mining industry, in the; East as being in' a very sound,position.,'-i,With careful investigation of properties by people who thoroughly know the business, and sound administration the value of a property and its possibilities could practically be assessed on a, commercial basis. 'The principal objections, as she saw them were over-estimation of values and overcapitalisation of companies. ," ■'."'.■