The use of phosphogypsum , potassium feldspar preparation of basic research
|School||Kunming University of Science and Technology|
|Keywords||phosphogypsum potassium feldspar reaction atmosphere potassium melting out rate|
Phosphogypsum is that main solid waste in wet process of phosphoric acid production. The utilization ratio of phosphogypsum in our country does not reach 10% at present. The problems of environmental pollution, land occupancy and resources waste initiated by phosphogypsum have already become the key of restricting sustainable development of phosphate fertilizer enterprise. Meanwhile, solubility potassium resource in our country is grave insufficient but the reserve of insoluble potassium resource such as potassium feldspar ore is very rich. The way that organically combine potassium feldspar and phosphorus gupse to produce potasium sulphate, and to make reasonableness use of potassium feldspar and phosphogypsum, has significant economic value and academic significance.In this paper, the influence of reaction atmosphere, materials ratio, particle size of raw materials and the type and amount of help flux to experimental indicators has been studied, through high temperature calcination in tubular reactor, taking phosphogypsum, potassium feldspar and coke as raw materials, and taking the theoretical weight loss rate, decomposition rate of calcium sulfate and potassium melt rate as indexes. The optimized formula has been founded.The study results show that:(1) Under the deoxidation atmosphere, oxide nature atmosphere and compound atmosphere, the calcination weightlessness rate and CaS04 decomposer rate of both phosphogypsum-coke and analytical pure gupse-coke system, have presentated an enhances trend with the reaction temperature raises; but break up outcomes are in great difference, the decomposition outcome under deoxidation atmosphere is mainly calcium sulfide, the decomposition outcome under oxide atmosphere and the compound atmosphere are mainly calcium oxide.(2) Under the deoxidation atmosphere, oxide nature atmosphere and compound atmosphere, the calcination weightlessness rate and CaS04 decomposer rate of both the phosphogypsum-coke-potassium feldspar and analyses pure gupse-coke-potassium feldspar system, have presentated an enhances trend with the reaction temperature raise; under the identical temperature, potassium melts out rates is minima under deoxidation nature atmosphere, potassium melts out rate is comparatively highly under the oxide atmosphere and the compound atmosphere.(3)For gaining higher potassium rate, adopt single factor experiment way to find the following conclusions:calcium silicon proportion is 1.2,coke dosages has exceeded upper limit of given experiment, still need to be increasd;coke granularity is in 160 mesh≤d≤140 mesh, helping flux is Na2CO3,25% of coke quality.(4) Though orthogonality experiment way to analyze the impact of potassium feldspar, phosphogypsum, coke and assistant over reaction. Have gained higher potassium melting out rate technological conditions. Optimize scheme is:the baking temperature is 1000℃, baking time is 1.0h, reacted in weak oxide nature atmosphere, helping flux dosages is 30% of potassium feldspar quantity, potassium melting out rate amounts to 90.0%.(5) Though XRD and infrared investigation way discussed reaction mechanism and verified that there existed potasium sulphate in calcination outcome.(6) Aiming at the waste residue that potasium sulphate have been extracted, carried the carbon separating progress to extracte aluminium, repeated waste residue has been used to prepare CBC compound material and has got first step result.