制浆废液降低普钙水分的应用研究

针对我国采用高临界流动水分的磷矿进行湿法生产普钙普遍存在产品水分达不到部颁标准的难题,直接采用制浆废液(利用其主要对环境有害成分之一--MNA作减水剂)进行降低普钙水分的研究和应用.实验结果表明,添加少量的减水剂MNA可显著降低国内朝阳、昆阳、浏阳和国外摩洛哥等单种磷矿以及昆阳-朝阳混矿的矿浆粘度和水分.采用国产昆阳-朝阳混矿进行工业生产试验结果表明,添加0.35%～0.4%干矿粉重量的减水剂MNA,不仅可使球磨添加水量从145 kg降至103 kg,矿浆含水量从30.5%降至27%,成品肥含水量从16.24%降至13.77%,而且可使有效磷从10.67%升至12.24%,转化率由86.57%提高到90.45%,矿浆细度由90.18%提高到93.12%.实验和工业生产试验表明,直接用造纸制浆废液降低普钙水分,既确保和改善了普钙的产品质量,又治理了环境污染,取得了较好的经济、环境和社会效益.

Study on reducing moisture of superphosphate by pulping waste liquor

In the light of the difficult problem that the water content of superphosphate produced by wet ball grinding method using high critical flow moisture phosphate rocks as materials is generally over the standard regulated by our country,the research and application of pulping waste liquor in reducing the moisture of superphosphate was carried out,in which the one of the main harmful components in the pulping waste liquor,MNA,was played a key role as a water reducer.The experimental results showed that addition of a little quantity of MNA could obviously reduce the viscosities and water contents of the mineral slurries of domestic Chaoyang,Kunyang and Liuyang phosphate rocks and Morocco phosphate rock as well as the mixed Kunyang-Chaoyang rock.The mixed Kunyang-Chaoyang rock was used in industrial test which exhibited that the water quantity added in the ball grinder,the moisture of the mineral slurry at the outlet of the ball grinder as well as the moisture of the final product could be decreased from 145 kg to 103 kg per ton product,30.5% to 27% and 16.24% to 13.77% respectively.At the same time,the effective phosphor,the conversion and the mineral slurry particle were increased from 10.67% to 12.24%,86.57% to 90.45% and 90.18% to 93.13% respectively when 0.35%~0.4%(of the weight of the dry mixed phosphate rock powder) of MNA was added.The experiment and industrial test indicated that directly using pulping waste liquor to reduce the water content of superphosphate was not only able to ensure and to improve the quality of superphosphate but also to treat the environmental pollution,exhibiting that a better economic,environmental and social profit can be obtained.