Potassium chloride beneficiation

Potassium Chloride. The principal ore encountered in the U.S. and Canadian mines is sylvinite [12174-64-0] a mechanical mixture of KCl and NaCl. Three beneficiation methods used for producing fertilizer grades of KCl ate thermal dissolution, heavy media separation, and flotation (qv). The choice of method depends on factors such as grade and type of ore, local energy sources, amount of clay present, and local fuel and water availabiUty and costs. 

Highly interesting results were obtained by Murata [42], showing very high efficiency of potassium chloride and somewhat lower efficiency of sodium chloride. Investigations on the effect of potassium and sodium nitrate are also noteworthy. They were found to have a beneficial influence only when a few per cent were used in greater quantity they have practically no effect. 

Froth flotation of the surface-sensitized pulp by vigorous aeration and agitation in saturated brine (density ca. 1.18 g/mL), first in a series of rougher cells with further refinement in cleaner units, produces a stable froth consisting almost entirely of beneficiated potassium chloride and an underflow of sodium chloride (particle densities of 1.984 and 2.165 g/mL), respectively. Potassium chloride recoveries from sylvinite by this procedure are 90 to 95% complete [22]. 

Froth flotation is used to raise the low mineral concentrations in ores to concentrations that can be more economically processed. A concentration of 25-30% is suitable for economical smelting of copper. The froth flotation technique was originally developed in about 1910 to raise the copper concentrations of the strip-mined ores of Bingham Canyon, near Salt Lake City [9], and was further perfected for the differential separation of lead, zinc, and iron sulfides at Trail, B.C., at about the same time [10]. Flotation technologies are now widely used for separations such as the beneficiation of low grade Florida phosphate ores from 30-40% to 60-70% concentrations of calcium phosphate (BPL), and the separation of about 98% potassium chloride from sylvinite, a natural mixture of potassium and sodium chlorides. It is also used for bitumen separation from tar sand, removal of slate from coal, and removal of ink from repulped paper stock preparatory to the manufacture of recycled paper stock. More details of these separations are discussed in the relevant chapters. 

If potassium hydroxide is used to raise the pH and hydrochloric acid is used to lower the pH then potassium chloride is formed (KCl). This is the most widely used combination, as KCl has beneficial qualities. 

The beneficial effects of potassium on blood pressure should reduce the occurrence of blood pressure-related cardiovascular disease. Potassium may also have protective effects that are independent of blood pressure reduction. This possibility has been tested in experimental studies conducted in rodents. In a series of animal models, the addition of either potassium chloride or potassium citrate markedly reduced mortality from stroke. Interestingly, these reductions occurred when blood pressure was held constant. Such data indicate that potassium has both blood pressure-dependent and blood pressure-independent properties that are cardioprotective. 

Dissolved mineral salts The principal ions found in water are calcium, magnesium, sodium, bicarbonate, sulphate, chloride and nitrate. A few parts per million of iron or manganese may sometimes be present and there may be traces of potassium salts, whose behaviour is very similar to that of sodium salts. From the corrosion point of view the small quantities of other acid radicals present, e.g. nitrite, phosphate, iodide, bromide and fluoride, have little significance. Larger concentrations of some of these ions, notably nitrite and phosphate, may act as corrosion inhibitors, but the small quantities present in natural waters will have little effect. Some of the minor constituents have other beneficial or harmful effects, e.g. there is an optimum concentration of fluoride for control of dental caries and very low iodide or high nitrate concentrations are objectionable on medical grounds. 

Sodium is an essential element and additions of sodium chloride to soils can provide increased yields of some plants. There is some degree of overlap in the roles of sodium and potassium in plant nutrition. Both Na and Rb are beneficial in K-deficiency. 

Efficient removal of oxygen is required to obtain optimum yields. Exposure to swelling agents such as 5% aqueous zinc chloride or potassium thiocyanate prior to grafting onto collagen did not increase the yield. However, the presence of a wetting agent proved beneficial. 

Mineral salts, for example those providing chloride, nitrate, carbonate, sulfate, phosphate, calcium, magnesium, sodium, potassium, iron, zinc, manganese and like ions are also incorporated in the media with beneficial results. As is necessary for the growth and development of other microorganisms, essential trace elements should also be included in the culture medium for growing the organisms employed in this invention. Such trace elements are commonly supplied as impurities incidental to the addition of the other constituents of the medium. 

Bollard and Butler (1966) in their discussion of functional elements include several others in addition to the above four. They state that fluorine, iodine, and selenium fall in this class for in some plant species they are metabolized, forming definite organic compounds. Bromine, rubidium, and strontium are also placed in this class because they exert a sparing effect on the utilization of chloride, potassium and calcium. Cobalt may perform that same function. They state further that our knowledge of the beneficial effects produced by aluminum, beryllium, and barium are not as yet adequate to justify including these in the group of functional elements. Further research will probably add other elements to this group. 

Is the inositol present abundantly in vesicular fluids and seminal plasmas of certain species of any functional value Perhaps, as Mann (4) suggests, the enormous amount of inositol present in boar vesicular secretion may be concerned with maintenance of the osmotic equilibrium of the seminal plasma in this species, since boar seminal vesicle fluid (unlike other pig body fluids) is almost devoid of sodium chloride, although it is quite rich in potassium. There are claims testicular (287) and ejaculated (293) spermatozoa can metabolize inositol to unidentified substances although one report (294) denies that ejaculated spermatozoa can oxidize this cyclitol. In any event there is no convincing evidence that seminal inositol is a major metabolic fuel or otherwise beneficial for spermatozoa. 

Sodium Begukaion.—Cortical deficiency is characterised by an increase in the urinary output of chloride, and a resulting fall in sodiiun, potassium and their ionic partners, chloride and bicarbonate, in the plasma. Conversely, administration of sufficient NaCl to keep the plasma level normal has a beneficial effect in the treatment of both experimental and Addisonian cortical deficiency. 

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