Method for preparing coal water slurry dispersant by using papermaking black liquor

Abstract

The invention discloses a method for preparing a new type of coal-water slurry dispersant by utilizing papermaking black liquor. The steps are: firstly filter the waste black liquor, then separate the filtrate with a semipermeable membrane, and separate the unpermeable precipitate, i.e. lignin, with After washing with 2-4 times the weight of water, add caustic soda, feed SO2 at 130-150°C, and dry in a water bath to obtain sodium lignosulfonate, then add ethylene glycol, water and concentrated sulfuric acid, and react under normal temperature and pressure 2h can; Utilize papermaking black liquor of the present invention to prepare the method for novel coal-water slurry dispersant, both papermaking waste black liquor has been effectively resourced and utilized, and a kind of novel coal-water slurry dispersant has been obtained again, The preparation raw materials have wide sources and low production cost, and have broad application prospects in the resourceful treatment of papermaking black liquor.

Description

technical field [0001] The invention relates to a method for recycling papermaking black liquor, in particular to a method for preparing a coal-water slurry dispersant by using papermaking black liquor. Background technique [0002] The paper industry is an industry with high consumption of energy and chemical raw materials, large water consumption, and serious pollution. The pulping and papermaking scale of my country's paper mills is small, the number is large, and the distribution is wide, lacking effective pollution control, and the raw material for pulping in my country is wheat straw fiber. Mainly, the utilization rate of raw materials is low, and the composition of black liquor is complex. Lignin is a by-product of the paper industry. It is contained in the black liquor of pulping and papermaking as the main component. It is cheap, rich in sources, and non-renewable. Biological resources, my country's paper industry produces 5 billion tons of papermaking black liquor ev...

AI Technical Summary

Problems solved by technology

Although it has a certain effect, the investment is large and the operating cost is too high. The investment in alkali recovery is more than 50 million yuan, which is only suitable for paper mills with an annual output of more than 30,000 tons.

Simultaneously, the content of silicon in grass black liquor is relatively high, so it is unsatisfactory to reduce the cost of alkali recovery and improve the recovery rate of alkali in technology. Acid analysis of lignin can make lignin products be recovered, but the lignin market is not sold well.