THE CARBINE CRUSHING.

Auckland Star, Volume XXII, Issue 144, 19 June 1891, Page 3

THE CARBINE CRUSHING.

KUAOTUNU BATTERY BEATS THE MOANATAIARI.

Mr. John Good hall has forwarded a lengthy report to tho legal manager of the Carbine mine, Kuaotunu, with regard to the trial crushing of quartz at the Moanataiari battery. He states thab three classes of ore wero forwarded for treatment. No. 1 is 5 tone of beat ore, and 401b of picked stone from the leader ; No. 2 is IOJ ions of second clas3 oro from the leader ; and No. 3, ten tons of ore from the main lode. Parcels of No. 2 and No. 3 ore had alroady been treated at the Kuaotunu Quartz Crushing Company's batten/, and parcala of No. 2 and No. 5 were also senb so as to teat tho ativing power of bho Kuaotunu battery. Ab that battery the stamped ore passed over mercury tablee and tho tailings wonb direct through Price's pans. Ab the Moanabaiari battery the stamped ore pasaed over mercury tables and blanket shakings, and the blanketings were washed off in berdans. The tailings were gathered in pits and treated in one of Eraser's pans. Ib appears from the Kuaotunu crushing returns thab 2dk tons of No. 2 oro and 14 tons of No. 3 ore were put through. On inquiry MrGoodhall found that 7 largo bags of quarte were accepted as one ton at the Kuaotunu battery, while 20 small ones wero taken as a ton at the Moanataiari battery. By measurement ib \Vas found that 3.V smull bags wero equal to one largo bag ; thus thab at"the Kuaotunu battery would bo ns 23 l-3rd to 20 ab tho Moanataiari battery. So instead of 23A tons of No. 2, and 14 of No. 3, the figures will bo 34£ and 16.J, and the result was aa follows :—No. 2, yielded 80oz lldwb of molted gold, equal to 2oz 6dvvb per ton : and No. 3, 16 j tons, 13oz 9dwt, equal to 17dwt. The total results from the Moanataiari battery were —including what was saved from tho pans—No. 1, 5 tons, 107oz sdwt, equal to 21oz 9dwt per ton ; No. 2, tons, '230z 19dwt, equal to 2oz 6dwt per ton ; and No. 3, 10 tons, 7oz 9dwt, equal to 15dwt per ton. It will be seen that with regard to the No. 2 parcel both returns aro equal, while in No. 3 the Kuaotunu battery yield is 2dwb ' better than the Moanataiari. That may be accounted for by there being a few bags of better orefrom near the Try Fluke boundary in that sent to the Kuaotunu battery. Ib is gratifying to know thab this test proved that tho Kuaotunu battery saves as much gold ac the Moanataiari, which lattor is considered one of the best on the Thames. With regard to the tailings Mr Goodhall states thab he does nob think any pan with a constant overflow is suitable for saving Kuaotunu goid, it being so tino that it passes away with tho mildest current of water. Before and after tho tailings wero treated in Fraser Bros.' pans, a good average of each parcel was sen 6 to the School of Mines for assay, with tho following result :—Tailings from No. 1, before treatment, 3oz lOdwt 14gr per ton; after treatment, 15dwt3gr; ISFo*2. before treatment, 3oz 2dwfe 23gr, after 4oz sd\vt 17gr; No. 3, before treatment, sdwt Igr, after treatment, no trace of bullion. With regard to No. 2 showing more trace after treatment than before, Mr Goodhall abates thab the proportion gathered is so smalJ thut it represents the concentrates of tha overflow, and therefore might easily contain more bullion per ton, which divided with the original amount would be far less. The value of the bullion is poor, being redacsd from 53s 6d per ounce, the value of the gold from the crushing, to 12s per oz. Ib is probable thab about one-third of the ore after crushing passes away in the overflow as sluices, and the whole amount after treatment in pans. Mr Goodhall adds : " The large amount of loss shown in No. 2 cannot help strengthening the view that a great loss occurs in the present modes of treatment. That there is bub little loss in No. 1 is only what might have been expected, for in free ores ths richer it is the easier ib can be savod. The loss in No. 3is bebter than ;;ould have been .j.y^'nted."