等离子体法分解锆石制取氧化锆工艺的研究

PREPARATION OF ZIRCONIA BY DECOMPOSING ZIRCON WITH PLASMA

用直流等离子装置进行了分解锆石制取氧化锆的实验室研究和扩大试验．研究了等离子体工作气体和送料气体流量、加料速度和锆石粒度等对锆石分解率的影响．结果表明,在等离子孤功率为50kW,工作气体流量为2500L／h,送料气体流量200L／h,加料速度为10kg／h的条件下,锆石分解率可达99．0％．同时研究了NaOH溶液浓度和用量、浸出温度和时间对氧化锆纯度的影响,在用12．5mol／LNaOH溶液,温度为144℃,浸出1h的条件下,氧化锆的纯度可达90．0％以上．产品符合制取锆刚玉的技术要求．

Laboratory study and pilot test have been conducted for preparation of zirconia by decomposing zircon with DC plasma device. Effects of the flowrates of plasma working gas and feeding gas, the feeding speed, the grain size of zircon, etc., on the decomposition rate of zircon have been studied. Results show that under the condition of plasma arc power 50kW, working gas flowrate 2 500L/h, feeding gas flowrate 200L/h and feedingspeed 10kg/h, the decomposition rate of zircon can reach 99.0%. Effects of the concentration and consumption of NaOH solution, the leaching temperature and leaching time on the purity of zirconia have also been studied. Under the condition of NaOH solution 12. 5mol/L,temperature 144℃ and the leaching time 1h, the purity of zirconia can attain to over 90.0%.The product is in line with the technical requirement for zirconium-bearing adamantine spar.