Study On Boron Extraction Process Of Brine Precipitation In Jiangling Region Hubei Province

In China,boron resources are relatively scarce,especially in recent years the boron magnesite resources used in industrial production are facing exhaustion.Now.it mainly aims at liquid boron mineral resources in salt lake and underground brine to meet the needs of various industries.The underground brine in Jiangling sag is rich in resources,its chemical type is chloride type,its composition is mainly sodium chloride and potassium chloride,and it contains abundant boron,lithium,bromine,etc.,all of them have high development grade.It has high comprehensive utilization and development value.This paper taked jiangling underground brine as the research object to study the process of boron extraction by precipitation.Boron content in brine for raw materials to achieve technological requirements of boron precipitation,evaporation analysis this topic first studied in the cooling analysis of sodium potassium boron enrichment regularity,to determine the NaCl-KCl brine system were satisfied when the evaporation of water at a rate of 66.10%.when the content of B2O3 in the solution of 2.10%,about 13 times of B2O3 in the brine concentration,sodium chloride and solid phase of B2O3 bring loss rate was 5.09%;After evaporation and concentration,the mother liquor was cooled to extract potassium,and the content of B2O3 in the mother liquor was 2.24%,the belt loss rate of B2O3 in the solid phase of potassium chloride was 0.77%,and the total belt loss rate of boron was 5.86%,which met the technical requirements of boron extraction by precipitation.In the study of the precipitation process of boron in the mother liquor,lime milk was used as the precipitant to extract boron from the mother liquor after potassium extraction.Determine the optimum operating conditions for lime dosing quantity was 7.85 g/100 g content,reaction temperature of 30?and reaction time of 2 h;Under this optimal condition,the boron precipitation rate was 95.88%and the boron content in the precipitation was 10.79%.The solubility of boric acid in calcium chloride solution was investigated by static equilibrium method.The experimental data were correlated with the Apelblat equation,empirical equation and ?h equation.The results showed that the solubility of boric acid decreases with the increase of calcium chloride content,but increased with the increase of temperature.Apelbiat equation,empirical equation and ?h equation could well correlate the solubility data of boric acid in different calcium chloride solutions,and the correlation coefficient was above 0.98,average relative error was less than 6.5%,and the maximum root mean square error was 1.46×10-3,the Apelblat equation and empirical equation had a good fitting effect compared with ?h equations.Finally,according to the measured solubility data,the technological conditions for the preparation of boric acid by calcium borate acidification were explored,and the optimal operating conditions were determined as adding acid for every 50 g of calcium borate was 26 mL,the concentration of hydrochloric acid was 30%,the reaction time was 5 min,and the agitation rate was 300 r/min.Under the optimal conditions,the yield and purity of boric acid were 95.56%and 92.95%respectively.