Transactions of the American Institute of Mining, Metallurgical and Petroleum Engineers Volume 55 - Softcover

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1917 Excerpt: ...feed was treated with a low pulp density. These tests gave fully as good results from the recovery standpoint in a considerably better grade of concentrate as those made on the round-table tailing under similar conditions. During Period 15A, wood creosote from the Crichton Pine Products Co. was used. During Period 15D, no creosote was used and the tailing assay increased from about 0.20 per cent. Cu to 0.32 per cent. Cu. During Period 15E, some creosote from the Rocker Timber Treating Plant, near Butte, was used, but gave a high tailing--0.42 per cent. Cu. During Period 15B, tar creosote from the Butte Gas Co. was used, with apparently good results, although the test was too short to be taken as conclusive proof of the value of this creosote as a flotation oil. (n) Round-Table Feed. Low Tonnage (50 Tons'). Pulp Heated to 70 F.--The tests (Period 16A) gave a tailing running 0.21 per cent. Cu, and a fair grade of concentrate. (o) Round-Table Feed. Pulp Heated to 70 F. High Speed of Agitators.--It was thought that by increasing the speed of the agitators the amount of feed treated might be increased without decreasing the recovery. The first nine agitators were used and their speed was increased from 265 r.p.m. to 363 r.p.m. The test (Period 16B) was of short duration, as the machine would have racked itself to pieces if operated very long at this high speed. While the test is too short to be conclusive, the indications are that the increased speed was a detriment rather than an advantage. It is thought that there is a critical speed at which the agitators should be run for the most efficient operation. If we go above this speed the power increases much faster than the capacity, and if we go below it we do not get a proper mixing of oil and acid with the pulp....