الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
The influence of agriculture on the country’s economic development is of vital importance, Cl characteristic which Egypt has in common with other developing countries s.
Potassium is the third most important fertilizer ingre¬dient in terms of actual tonnage used throughout the world for plant nutrient purposes. The requirements for potassium for normal growth and development in all living organisms are well established d.
The element potassium occurs in abundance over wide spread areas of the earths surface as a component of various rocks, minerals, and brines. Most of these potassium-bearing materials have limited value as plant nutrients and require further processing to convert them into economically useful potassium fertilizers.
It is appropriate that the industrial production and crop use s of potassium should be re vie we d at the pre sent time, because vastly increased quantities of potassium fertilizers will be required to supply food for increasing in human popu¬lation specially in developing countries like Egypt. So, it is the object of this thesis is to investigate the possibili¬tie s of extraction of potassium from Egyptian local sources. Cane blackstrap molasses are produced in Egypt. The process of extraction of potassium salts from these molasses is not e economic. Orthoclase feldspars are found in Aswan. The potassium content of these rocks is low and greater con¬centration is seldom possible by physical methods, moreover, the recovery of potassium necessitates expensive chemical treatrment • The most important raw materials in Egypt are sea water and bitterns obtained after recovery of sodium chloride. Dilute solutions such as sea water have been particulary costly to process. Enormous volumes of sea water are required to recover comparatively small quantities of potassium salts. Thus, bitterns are considered the best raw material, since only small volumes of bitterns are required to recover comparatively lar@6 amounts of potassium salts, and the process is easier to control and more cheaper. Potassium salts can be obtained from bitterns by fractional crystallization. The oldest of all crystallization techniques is that employing solar evaporation. The extraction of potas¬sium from any sort of complex mucture is always complicated by the presence of sooium. Although the separation of potassium from sodium, ~s in @Sneral quite difficult to accomplish with¬out extensive processing t some chemical re actions have been reported which represent the possibility of selective recovery of potassium in large yields. These methods depend on the precipitation of potassium from sea water by sodium bismuth thiosulphqte or by sodium