钛白粉生产工艺优化与设备改进

Process optimization and equipment renovation of titanium dioxide

某公司1.5万t/a硫酸法钛白粉生产工艺存在"三废"排放量大、能耗高、生产成本居高不下等问题。针对以上问题对钛白粉生产工艺进行了优化,对设备进行了改造,主要包括酸解反应过程、煅烧尾气处理过程以及转窑系统等,最大程度地降低了钛白粉的生产成本。实践结果表明:将废酸回用于酸解反应,可将酸解率提高并稳定在95%以上,每吨钛白粉硫酸消耗从4.52 t下降到4.25 t;将偏钛酸二次洗水用作煅烧尾气喷淋水再回用到偏钛酸一次洗水,每年可节约蒸汽5.9×103t;改造转窑系统,提高了燃烧效率,每吨钛白粉煤气消耗从780 m3降至533 m3。通过以上工艺优化和设备改进,累计可降低钛白粉生产成本912.8元/t。

There are many problems, such as serious ＇three wastes＇, high energy consumption, and high cost,in a company＇s titanium dioxide production process by the sulfuric acid method with annual output of 15 000 t.By means of process optimiza- tion and equipment renovation, the titanium dioxide production cost has been greatly reduced from the acidolysis process, calcination off-gas treatment process ,and the rotary furnace system etc..It has been demonstrated that the acidolysis ratio rate was improved and stabilized more than 95% ,while the waste acid was reclaimed to the aeidolysis reaction, and the acid con- sumption for producing 1 t TiO2 reduced from 4.52 t to 4.25 t;5.9x103 t vapor could be saved every year,while the secondary washing water of metatitanic acid was used as spray water for off-gas in calcination process, and then returned to the primary water washing process ; the rotary furnace system was rebuilt to increase combustion efficiency, and the consumption of coal gas for producing 1 t TiO2 was sharply reduced from 780 m3 to 533 m3.The above measurements brought a total titanium diox- ide production cost reduction of $ 912.8 per ton on an accumulative basis.