改进磷酸浓缩换热方式 提升浓缩运行周期

针对全球磷矿资源贫化,浓缩装置产能、开车周期大幅下降的现状,对浓缩工艺进行改造:采取稀磷酸不过滤澄清,并经蒸汽预加热至80℃进入浓缩系统;在稀酸中添加抗沉积剂,减缓结垢;控制适宜浓缩磷酸浓度和优化石墨换热器结垢清洗工艺。改造后浓缩产能提升30%,运行周期达28~30 d,提高DAP产量相当于年增产值3 600万元,节约蒸汽费用14.2万元。

Increase of running period of concentration process by improving the ways of heat-exchange in phosphoric acid concentration

For the deficiency and dilution of phosphate rock, the running period and running period of concentration process are decreased. Some measures are adopted including the dilute phosphoric acid is preheated to 80℃ and then delivered to concentration process without filtration and clarification; anti-deposition agent is added into phosphoric acid to reduce scaling; the concentrated phosphoric acid is controlled at proper concentration, and the washing process is optimized for graphite heat exchanger. After the reform, the capacity of concentration is increased by 30%, running period is prolonged to 28-30 d, production value of yield of DAP is increased with the value of 36 million RMB Yuan per year, the cost of steam is saved by 0.142 million RMB Yuan.