Method for realizing vacuum dewatering of caustic sludge by adopting engineering mode

Abstract

The invention provides a method for realizing vacuum dewatering of caustic sludge by adopting an engineering mode. The method is characterized by comprising the following steps that: a vertical drainage channel is arranged in the caustic sludge, and a horizontal water collection layer is arranged on the surface of the caustic sludge; the inside of the horizontal water collection layer is provided with pipes; a vacuum membrane covers the caustic sludge for sealing; and water and air in the caustic sludge are continuously pumped out by vacuum equipment, and after a period of time, the water content in the caustic sludge is greatly reduced, so that the dewatering effect is achieved. The method for realizing the vacuum dewatering of the caustic sludge by adopting the engineering mode is lower in engineering cost and shorter in construction period. The caustic sludge of which the length is 10.0 m and the water content is not more than 70 percent is taken as an example, the entire cost in unit area is less than 107 yuan, and the construction period is less than 70 days. Moreover, the method also has the advantages of simultaneously meeting the requirements of environmental protection, large-scale utilization, low cost and easy popularization, and having obvious social and economic values and good application and development spaces.

Description

technical field [0001] The invention belongs to the technical field of environmental geotechnical engineering, and specifically relates to a new technology for dehydrating ammonia-alkali waste slag by using engineering means (non-chemical means) and improving strength for comprehensive treatment and utilization. Background technique [0002] During the production of soda ash by the ammonia-soda method, a large amount of ammonia distillation waste liquid is discharged (about 10m3 per ton of soda ash produced) 3 Waste liquid and waste residue) are stored by damming the slag yard. Alkali slag occupies land, erodes soil, destroys vegetation, pollutes the environment, and consumes a lot of human resources and property to manage, which restricts the further development of the enterprise and directly hinders the enterprise from becoming stronger and bigger and local The coordinated progress of social economy is the "bottleneck" problem that the soda ash industry needs to solve. Fu...

AI Technical Summary

Problems solved by technology

However, because the alkali slag has strong hydrophilicity, high water content (more than 170%), and low strength, it must be dehydrated before it can be used. For this reason, two attempts have been made at home and abroad: one is to add a dehydrating agent or solidify the alkali slag. However, it is not difficult to see that the use of chemical means is not only costly, does not have a reasonable input-output ratio, but also causes secondary pollution, which does not meet the requirements of environmental protection, so this method is limited to indoors. It is only a small amount of research, and there is no feasibility for large-scale promotion and application; the second is to use large-scale filter press equipment, the purchase cost is relatively high (domestic is 5-10 million yuan / set, imported is 1.2-1.6 million US dollars / set), and the operation The cost is too high (1 ton of soda ash filter press costs 30-40 yuan, taking the annual treatment of 1.3 million tons of alkali slag as an example, the annual operating cost is 39-52 million yuan), so this method cannot be widely used

In view of the above problems, a large amount of alkali slag has not been utilized at present, and it is still stored for a long time in the slag field. There is no scientific, reasonable and economically feasible alkali slag dehydration technology at home and abroad.