Reasearch On Preparation And Effectiveness About Silicon Fertilizer From Coal Ash

Silicon fertilizer is a new mineral fertilizer of high quality, high efficiency, no poison and wide used. At present, the silicon fertilizer generally has the problem of low content of soluble silicon and high price. So it is difficult to be extensively used.The preparation and the application of silicon fertilizer from coal ash and the paper-making black liquor would be studied in this thesis, and at the same time, this fertilizer would be beneficial to the sustainable development of agriculture.In this thesis, the factors such as the ash granularity, the calcinating temperature, calcinating time, alkalinity and additive, etc, were firstly studied by the orthogonal test. The results indicated that the smaller granularity of coal ash and the higher concentration of KOH, the more favorable to increasing the soluble content of silicon in coal ash. But if the alkalinity was too high, the silicon fertilizer produced with alkali liquor soaked ash was easily affected by damp, which would affect the following experiments. Solid additives such as potassium carbonate and calcium carbonate would not have the same problems above, and also increasing the content of soluble silicon. The fertilizer roasted at high temperature should be cooled naturally.According to the preliminary study, the paper-making black liquor was considered to be the activated reagent because of its high alkalinity and high energy contains, to produce the silicon fertilizer. The results indicated that the even mixture of catalyst C3, with the mixture of the coal ash and the paper-making black liquor in the ratio from 5:1 to 8:1 were dried on the resistance furnace, then calcinated in the muffle furnace at 750~800℃ for 10 minutes to obtain the silicon fertilizer with the soluble silicon above 30 percentage.The greatest withdrawal and the eluviating rule of the beneficial elements (Cu, In, Mn, Se) and the heavy elements (Cr, Cd, Hg, Pb) were researched, for...