Electrostatic K-Feldspar/Na-Feldspar and Feldspar/Quartz Separation: Influence of Feldspar Composition

This article aims at contributing to the possibility of electrically separating K-feldspar/Na-feldspar and quartz/feldspar, investigating the behavior of mixtures composed of K-feldspar, Na-feldspar, and quartz concentrates. The findings highlight the importance of preheating the material and of interparticle contact. Tests conducted on binary mixtures of K-feldspar/Na-feldspar, K-feldspar/quartz, and Na-feldspar/quartz showed that it is possible to achieve satisfactory results in the separation of these species, by triboelectrical charging of the material, preheated to temperatures above 100°C, using a free fall chamber. Tests carried out on ternary mixtures have demonstrated that additional pretreatment with HF solutions improves the results.     

某中低品位钾长石无氟浮选试验研究

采用无氟浮选工艺对低品位钾长石矿进行了浮选试验研究,试验结果表明,采用磨矿-沉降脱泥-一粗一精-强磁选的选矿工艺流程,在磨矿细度为-0.074mm含量占50%,粗选pH为4,油胺与石油磺酸钠用量分别为800g/t、1600g/t时,可获得产率59%,K2O+Na2O品位为12.55%的长石产品,同时可获得产率为19.94%,SiO2品位为97.12%石英产品。此选矿工艺为该长石资源的综合利用提供了参考。     

硅酸盐细菌的选育与解钾性能研究

从合肥郊区玉米地里分离出菌株经生化实验初步鉴定为硅酸盐细菌，在室温下，以钾长石为底物，用未驯化硅酸盐细菌浸出8、16、24天后测水溶性钾离子平均浸出率分别为0．31％、0．51％、0．58％；而第二次驯化硅酸盐细菌浸出时在同样条件下水溶性钾离子平均浸出率分别为0．69％、1．17％、1．49％，驯化后细菌浸出比未驯化细菌浸出时细菌解钾能力提高了2倍以上。     

Decomposition behavior of CaSO4 during potassium extraction from a potash feldspar-CaSO4 binary system by calcination

The extraction of potassium from a tablet mixture of K-feldspar ore and CaSO_4by roasting was studied with a focus on the effects of the decomposition behavior of CaSO_4on the potassium extraction process.The roasted slags were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy,and thermogravimetric(TG)analysis.The XRD analysis revealed that hydrosoluble mischcrystal K_2Ca_2(SO_4)_3was obtained by ion exchange of Ca~(2+)in CaSO_4and K~+in KAlSi_3O_8.Meanwhile,the intermediate product,SiO_2,separated from KAl Si_3O_8and reacted with CaSO_4to decompose CaSO_4.The SEM results showed that some blowholes emerged on the surface of the CaSO_4particles when they reacted with SiO_2at 1200°C,which indicates that SO_2and O_2gases were released from CaSO_4.The TG curves displayed that pure CaSO_4could not be decomposed below 1200°C,while the mixture of K-feldspar ore and CaSO_4began to lose weight at 1000°C.The extraction rate of potassium and decomposition rate of CaSO_4were 62%and 44%,respectively,at a mass ratio of CaSO_4to K-feldspar ore of 3:1,temperature of 1200°C,tablet-forming pressure of6 MPa,and roasting time of 2 h.The decomposition of CaSO_4reduced the potassium extraction rate;therefore,the required amount of CaSO_4was more than the theoretical amount.However,excess CaSO_4was also undesirable for the potassium extraction reaction because a massive amount of SO_2and O_2gas were derived from the decomposition of CaSO_4,which provided poor contact between the reactants.The SO_2released from CaSO_4decomposition can be effectively recycled.     

碳酸钾助熔焙烧分解钾长石热力学实验研究

实验探讨了钾长石 碳酸钾体系热分解反应热力学过程，以钾长石分解率为目标函数，正交实验表明：最佳焙烧温度为860℃；钾长石：碳酸钾加入量=l：1．2；最佳焙烧时间60分钟；生料粒度60～80目。并用DTA/TG和X粉晶衍射进行分析，拟合热力学数据，初步分析了反应机理。     

煅烧钾长石生产硅钙钾肥的矿物组成研究

采用钾长石矿和石灰石为原料,在1180 ～1400℃温度范围内烧结制备硅钙钾肥.研究了烧结温度和生料配比对熟料矿物及其演化的影响,以及熟料矿物存在形式与有效营养元素含量之间的关系.结果显示,钾霞石、假硅灰石、钙铝黄长石等是硅钙钾肥中比较理想的熟料矿物;提高烧结温度有利于得到有效K2O含量和有效SiO2含量高的硅钙钾肥.提出了硅钙钾肥配料的反应方程式,对获得有效K2O含量高的硅钙钾肥,提高钾长石钾转化率,避免施肥造成农田板结等方面具有指导意义.     

The extraction of potassium from K-feldspar ore by low temperature molten salt method

The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO₃, NaOH, H₂O and K-feldspar ore, particle size of K-feldspar ore, reaction temperature and time were investigated, respectively. In addition, the optimum condition for this method was determined by a series of condition experiments. What was more, the K-feldspar ore and the leach residue after reaction based on the above optimum condition were analyzed by XRD, SEM and EDS, separately. The results of which indicated that the mechanism of extraction of potassium for this method was according to the ion exchange reaction between sodium ion and potassium ion, and the extraction ratio of potassium had an obvious improvement than that of traditional methods, which could reach up to 96.25%. Therefore, this method can be a feasible solution to extract potassium from K-feldspar ore for its low energy consumption and high efficiency.     

Kinetics on leaching of potassium from phosphorus–potassium associated ore in HCl–H3PO4 media

In order to relieve the equipment corrosion, reduce chlorine and increase phosphorus contents in leaching solution, the leaching behavior of potassium from phosphorus–potassium associated ore in the mixed acids of hydrochloric acid and phosphoric acid was investigated. The effects of various factors, such as mass fraction of hydrochloric acid, solid-to-liquid ratio, material ratio (CaF₂ dosage (g)/mass of ore (g)) and leaching temperature were comprehensively studied. It was found that the dissolution fraction of potassium can reach more than 86% under the optimum conditions of leaching temperature 95 °C, HCl concentration 10%, leaching time 6 h, solid/liquid ratio 1:5, and material ratio 0.1. In addition, the leaching kinetics of potassium was successfully modeled by a semi-empirical kinetic model based on the classic shrinking core model. The data showed that the leaching process of potassium was controlled by the product layer diffusion and the apparent activation energy for the process was found to be 54.67 kJ/mol over the temperature range from 65 to 95 °C.     

An efficient methodology for utilization of K-feldspar and phosphogypsum with reduced energy consumption and CO2 emissions

The issues of reducing CO2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO2 with reduced CO2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the high-temperature co-reaction significantly facilitated the reduction of phosphogypsum to SO2 and the exchange of K+(K-feldspar) with Ca2+(CaSO4 in phosphogypsum). The reaction parameters were systematical y investigat-ed with the highest sulfur recovery ratio of~60%and K extraction ratio of~87.7%. This novel methodology possesses an energy consumption reduction of~28%and CO2 emission reduction of~55%comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.     

一种钾长石的OSL研究

OSL是一种新的断代方法,本文报道了钾长石OSL断代的初步研究。