Research On Technology Of Leaching Potassium From Water-insoluble Potash Ore And High Value Of By-products

There is a shortage of soluble potassium resources in our country,which has high external dependence.However the non-water-soluble potassium mineral resources are extremely rich,with a wide range of species and distribution.At present,the bottleneck for the production of potash fertilizers from non-water-soluble potassium resources is mainly worring about the economic benefits,due to problems such as excessive energy consumption,low resource utilization,and insufficient added value of by-products.In order to reduce the cost of extracting potassium from water-insoluble potash and realize the comprehensive utilization of non-water-soluble potassium resources,this project used the potash feldspar ore,from Tongren,Guizhou Province,as a raw material to explore and optimize the process of“auxiliary roasting-water extracting potassium”.In the process,a sodalite zeolite molecular sieve and a light-absorbing sound-absorbing material were synthesized using the potassium-added tailings,and the closed circuit of process and the comprehensive utilization of resources were realized.Based on this,the transformation mechanism of mineral crystal phases between feldspar and zeolite was studied.The theory of homologous genetic effects of stone skeleton structures is expected to provide technical and theoretical support for the industrialized practice of potassium melting extraction technology.The main results are as follows:1.The influence of various types of composite additives,particle size,air flow,and the addition of anthracite on the procce of potassium melting extraction were investigated.Under the optimal conditions the extraction rate of K can be stabilized at 90%or more and the highest can reach 95.48%.Experiments show that the introduction of Na₂CO₃ into Ca Cl₂ system can greatly reduce the amount of Ca Cl_2,and significantly increase the extraction rate of K.This is due to the presence of Na can reduce the melting point of the molten salt system,thereby reducing the reaction temperature and energy consumption.On the other hand Na⁺can avoid high Ca²⁺ion oncentration gradient,and directly exchange with K⁺.2.Potassium extraction tailings were used as the sole source of silicon and aluminum to optimize the hydrothermal synthesis of sodalite zeolite and cancrinite zeolite.The sodalite zeolite can hydrothermally synthesize in the temperature range of 80¹80?,time 3⁴8h and Na OH concentration more than 10%.Continued elevated temperatures and prolonged time will cause the sodalite to transform into cancrinite.Adding an appropriate amount of aluminum source or HF can strengthen the crystallization process of sodalite.The sodalite prepared by adding HF has a good selective adsorption property for K⁺and the K⁺adsorption capacity is 47.12 mg/g at room temperature of 20?,and almost no Na⁺adsorption.3.A light-weight sound-absorbing material with a density of 1.12 g/cm³ has been successfully synthesized using potassium extraction tailings.This material has both the characteristics of pores absorbing ability and layers resonant ability at the same time,so that it has excellent medium-high frequency sound absorption performance.And the absorption coefficient for sound waves above 800Hz is greater than 0.6,and the absorption coefficient at around 1200 Hz is more than 0.95.4.The theory of homologous genetic effects of feldspar skeleton structure were proposed and the skeleton deconstruction principle of"Si-O bond in Al-O-Si structure breaks first"should be obeyed.The feldspar framework structure is very stable.In the process of potassium melting extraction,hydrothermal crystallization,and high-temperature sintering,the basic structure of the 4-and 6-membered rings remain unchanged.Only the deconstruction and recombination occur under varying degrees of reaction state.This theory can explain the symbiotic transformation of feldspar,feldspathoid and zeolite under geological conditions,and can provide theoretical support for the prospecting,development and high-value utilization of feldspar mineral resources.