SIMPLE PLANT

In 1996 the Minerals Separation, Ltd., purchased from the Block 10 company 60,000 tons of high-grade slime, and began the erection of a plant to treat this sort of material on a joint arrangement with the Sulphide Corporation, which company had large dumps of the same sort. This venture was one of the most interesting in the history of the application of flotation processes. The material treated is practically all finner than 100-mesh, and 82% was finer than 200-mesh. The plant was built in 1907, and it waw originally intended to re-treat the floation-concentrate on tables, and separate the lead sulphide from the zinc sulphide. This re-treatment scheme failed, however, and there being at that time no market for the mixed concentrate, the plant was shut down. During 1909 there was some demand for the mixed product on the part of zinc buyers and for experimental smelting* work on mixed sulphides, and the plant was run for a time. In 1910 a market was opened in Norway for mixed leadzinc concentrate, and the plant was operated long enough to fill a contract.

It is safe to say that such excellent recoveries on such a slimy material in a concentrate practically pure sulphide were never before secured by any form of mechanical concentration.

MINERALS SEPARATION, LTD.

In 1906 this company bought a large dump of lead-mill tailing from the Sulphide Corporation, and during 1907 a plant was constructed.* Profiting by lessons learned from earlier experiences, this mill did good work from the start, and has treated nearly 560,000 tons of dump material assaying 20% zinc. 6.2% lead, and 5.902. silver, and produced 218,000 tons of concentrate assaying 47-3% zmc> 9-8% lead, and noz. silver. No re-treatment of the concentrate is given in this plant.