Extraction of Potash from Polyhalite

Abstract

INDUSTRIAL AND ENGINEERING CHEMISTRY 991 or compensated for, when substituting reclaim for rubber, by taking diluents or excess filler from the rubber stock and by adding reenforcing material to the reclaim stock. They failed to realize that the same measures which would improve the reclaim tread could be applied to the base stock.If it were true that, due to the plasticizing effect of the reclaim, it would be possible to carry higher black loading in the reclaim tread stock with the same ease of handling, there would be some weight to the argument that the reclaim can be compensated for by adding black. Factory practice does not show this to be the case. On the contrary, the added black must be considerably reduced to keep the same handling conditions. If it were possible to process the reclaim stock with higher black, then it would also be possible to add more black to the non-reclaim stock and keep the differential in road wear.Since this is the case, if the non-reclaim tread stock is taken with no diluent or excess zinc oxide and with as much black loading as can be processed, then it is not possible to make compensation for the effect of the reclaim. These facts were put forth very clearly by Cranor (ß), who states that "A better tread can be made without reclaim than can possibly be made with it."The series in the present paper was not designed primarily to show the extent to which wear will fall off with the use of reclaim in a series of practical tread stocks. However, since no compensation for its effect is possible, the wear in such a series would fall off even faster than in the series in this paper, for in the latter diluent materials were added to the non-reclaim stock. Therefore, it can be said that up to 20 per cent, the use of reclaim will cut down the resistance to road wear by approximately the percentage used. This is essentially the conclusion reached by Holt and Wormeley (3). Their method was severely criticized by Bierer and Davis, but considering that their base stock was as stiff and tough as was considered practical at the time, this criticism was not justified and their conclusions were essentially in line with the facts. AcknowledgmentThe writer -wishes to express his appreciation to W.W. Vogt for valuable suggestions and criticism.

Potassium Sulfate from Syngenite by High–Temperature Extraction with Water

“…The preceding tests were based on dry syngenite entering the first stage. However, it would be desirable to send the wet syngenite product obtained from polyhalite by a solution process (16) directly to the high-temperature extraction, since this would eliminate intermediate drying. The use of syngenite containing 23 per cent of free water on the wet basis3 was simulated in experiment 87 by using more water in the first stage than in the second.…”

Texas-New Mexico Polyhalite as Source of Potash for Fertilizer

“…Five processes, with variations, for the treatment of polyhalite have been described by members of the Potash Research Laboratory of the Bureau of Mines (17, 18, £8), and detailed preliminary cost estimates have been made for the first two of these ( 28). Sehoch has patented (11)(12)(13)(14)(15)(16)(17)(18) processes which are similar in concept but differ in some details, while the Standard Oil Development Company (U¡) and Ransom (8) have patented still another type of process. A third line of attack has been considered by Hill and Adams (,:>), and a paper by Fraas and Partridge (£) describes a process differing radically from any hitherto proposed.…”

“…The hot extraction of calcined polyhalite is a basic operation in Bureau of Mines processes 1, 2, 3, and 4, described in detail elsewhere (17)(18)(19)28), and is specified in the patents of ). The original publications and patents should be consulted for experimental data and description of process steps, including the recirculation of schonite.…”

“…This complete conversion of the calcium sulfate content of polyhalite into syngenite is a basic operation in Bureau of Mines process 4 and its modifications. Details concerning processes 4 and 5 are given by Storch and Fragen in recent publications (18,19).…”

“…This possible by-product must meet the competition of established industries which produced the following products in 1927 (23): Magnesia. Storeh and Fragen {18, 19) have described experiments showing that magnesia may be recovered from the waste magnesium sulfate liquors by treatment of the latter with ammonia and carbon dioxide to precipitate MgC(As. (NH4)2C0:i.4H20, which is separated and calcined.…”