The Mineralogical Study And Flotation Process For Phosphorus And Potassium Associated Ore And Phosphate Tailing Of Yichang Area

Nitrogen, phosphorus and potassium are indispensable nutrient elements of thegrowth of the crops. Although phosphorus mineral resource is rich in our country, highquality phosphorite is scare. Although insoluble potassium resource is rich, solublepotassium is scarcity. Potash fertilizer is mainly dependent on import. It is an effectiveway to develop vigorously low-grade phosphate ore and insoluble potash resource forour fertilizer industry.The grade of phosphorus and potassium in phosphorus-potassium associatedmineral from Yichang area is low, so it has no economic value if utilized solely. Atpresent, simple storage is the main treatment method for most of phosphate tailingsresidue so that it causes extravagant environmental stress and resource wasteComprehensive utilization of phosphorus and potassium associated ore and phosphatetailing has significant economic and social benefits.In this paper, mineralogical characteristics such as the mineral composition, particlesize, structure and gangue’s dissemination of phosphorus and potassium associated orewere studied. The flotation process study of phosphorus and potassium associated orewas made based on the mineralogy. The experimental project which includes twiceroughing and once cleaning was determined against the difficulty of low contentphosphorus and high content magnesium. The main conclusions are as follows:(1)The main valuable minerals of phosphate and potassium associated ore arepotash feldspar, collophane while the gangue minerals are quartz, pyrite and a littledolomite. The content of potash feldspar, quartz, collophane and pyrite are67%,11.46%,6.54%,2.42%respectively. The collophane was floated in the form of irregular particleadhesion with pyrite and quartz which belongs to grained dissemination. Potash feldsparmainly exists in the shape of grain and sheet structure and some quartz are dip dyed inthe potash potassium. Dissemination of gangue minerals fine using day mineral asinclusion, so gangue mineral is separated by grinding.(2)Quartz and potash feldspar flotation are studied respectively. In the same concentration of dodecyl amine solution, yield of the two minerals increase first and thenstay almost the same with pH value (1~10).The difference of yield is obvious in acidmedium than in alkaline medium. When the two minerals are in the same sodiumdodecyl benzene sulfonate solution, yield of potash feldspar has negative correlation withpH value while quartz yield is not influenced obviously by pH value. Hydrophobicity inthe surface of the two minerals in combined collector using dodecyl amine and sodiumdodecyl benzene sulfonate is higher than in single collector.(3) The phosphate concentrate whose grade of P2O5is16.2%was obtained at60℃using TSM-46as direct flotation reagent and phosphorus and potassium associated orewhose P205grade is4.7%. The remaining minerals in flotation cell are feldsparpotassium and quartz after removing magnesium and phosphorus by scavenging. Theseparating effect of feldspar potassium and quartz using dodecyl amine and sodiumdodecyl benzene sulfonate as collectors was also studied. Based on single mineralflotation, the optimum process parameter of direct flotation feldspar in acid conditionwas determined as follows:pH value of pulp is2,the concentration of pulp is50%,the concentration ofdodecyl amine is400g/t and the concentration of sodium dodecyl benzene sulfonate is50g/t. The content of K2O was increased from8.95%to11.35%and yield could achieve52%adopting above process.(4)According to removing magnesium from phosphate tailing, phosphate tailing ofYichang area was studied systematically. On the condition that grinding fineness is-0.074mm which occupies95.23%，sulfuric acid and phosphoric acid were used as pHregulator and inhibitor for collophane and TSM-96was used as collector for dolomite,low grade phosphate tailing which includes P2O56.63%, MgO11.46%could reachdegree of phosphate concentrate which consist of25.32%P205and1.34%MgO.(5)Acting mechanism of collectors and minerals were analyzed and studied throughelectric potential measurement and infrared spectroscopy. The analysis showed that pointof zero charge of feldspar potassium and quartz were1.88and2.42separately and theyhad the same charge property in pure water. For similarity of electric potential in dodecyl amine solution, floatability became less diverse only in physical adsorption aspect. Themain adsorption forms of dodecyl amine in feldspar and quartz surface include: amineion’s electrostatic incorporation, association adsorption between amine molecular andadsorption by hydrogen bonds interaction. Also they have accordance in existence formand absorbability in two minerals surface.