从副产锌泥制备饲料级氧化锌

Preparation of feed grade zinc oxide from by-product zinc oxide mud

研究了以次硫酸氢钠甲醛副产锌泥为原料,经化浆、净化、过滤、洗涤、干燥、煅烧制备饲料级氧化锌的工艺过程,重点考察了制备工艺中除杂条件以及煅烧温度和煅烧时间对产品质量的影响。结果表明:采用去离子水化浆,采用质量分数为27.5%的过氧化氢水溶液氧化除去少量次硫酸氢钠甲醛,以锌粉置换出重金属,再用硫化钠作沉降剂除去剩余的微量的重金属,控制煅烧温度为900℃、煅烧时间为4 h,可制备出纯度达到99.5%的饲料级氧化锌产品。经检测,制备的氧化锌符合HG/T 2792—1996《饲料添加剂氧化锌》一等品标准。

Technology process for preparation of feed grade zinc oxide with by-product zinc oxide mud from formalde- hyde sulphoxylate production was studied. Process includes pulping, purifying, filtering, washing, drying, and calcining. Influ- ences of purifying conditions, calcining temperature, and time on product quality were emphatically investigated. Results showed the best process conditions were as follows： adopting deionized water to make pulp, using H2O2 solution with mass fraction of 27.5% to remove tiny formaldehyde sulphoxylate,employing zinc powder to replace heavy metals,then taking sodium sulfide as precipitator to eliminate the remained trace heavy metals, and controlling the calcining temperature at 900℃ and calcining time for 4 h. Under those conditions the purity of the obtained feed grade zinc oxide reached 99.5% and its quality has met the first grade requirement in Standard of HG/T 2792--1996.