Composite scale inhibitor for blast furnace gas washing water, and preparation and use method thereof

Abstract

The invention discloses a composite scale inhibitor for blast furnace gas washing water, which is composed of a dispersant S and a scale inhibitor P that are prepared respectively, wherein the dispersant S includes, by mass, 1-3% of sodium polymethacrylate, 3-5% carboxymethylcellulose, 5-8% of sodium alginate, 0.5-2% of sodium laurylphosphate, and the balanced being water; the scale inhibitor P includes, by mass, 6-8% of sodium ethylenediaminetetramethylenephosphonate, 5-8% of S-carboxyethyl thiosuccinic acid, 3-5% of polyaspartic acid, 4-6% of ethylenediaminetetramethylenephosphonic acid, 5-8% of ammonium tetramethyloxalate, 3-6% of 4-hydroxybutyl acrylate, and the balance being water. The invention also discloses a preparation and use method of the composite scale inhibitor. The composite scale inhibitor has the scale inhibition rate of more than 96% on the blast furnace gas washing water, thereby achieving a stable scale inhibition effect.

Description

technical field [0001] The invention relates to a scale inhibitor, in particular to a composite scale inhibitor for blast furnace gas washing water and its preparation and use method. Background technique [0002] A large amount of blast furnace gas is produced during the blast furnace ironmaking process, which contains a large amount of dust and flammable components. The waste water produced by washing the harmful substances in the blast furnace gas through the contact of gas and water is the blast furnace gas washing water. During the recycling process of blast furnace coal washing and washing, a large amount of Ca 2+ , Mg 2+ 、Ba 2+ , CO 3 2- , SO 4 2- , F - and other scale-forming ions, causing scaling on water pipes, cooling towers, and pool walls. Common in blast furnace gas scrubbing water is CaCO 3 Scale, CaSO 4 scale, fluoride, and contains a small amount of BaSO 4 Dirt and so on. While scaling, some corrosion products are also formed, such as FeCO 3 , F...

AI Technical Summary

Problems solved by technology

[0005] Under normal water quality conditions, traditional chemical scale inhibitors can achieve a scale inhibition rate of over 80%. However, under the current high-salt, high-alkalinity, and high-hardness water conditions, traditional chemical scale inhibitors mainly have the following deficiencies: One is that the scale inhibition rate is low, and it is difficult to reach 80% of the scale inhibition rate, which will easily lead to serious scaling in the blast furnace gas washing water system; the other is that the property is unstable and the action time is short. In actual use, it needs to be treated with water every day Injecting antiscalants into the system increases labor costs; third, in order to alleviate the scaling of pipes and equipment in the blast furnace gas washing water system characterized by high salt, high alkalinity, and high hardness, the system needs to be drained, and the low scale inhibition rate will Increased pipeline fouling and equipment fouling lead to an increase in the frequency and volume of sewage discharge in the system. At the same time, because the blast furnace gas washing water contains a large amount of inorganic ammonia nitrogen and cyanide, the follow-up also increased the treatment of ammonia nitrogen and cyanide in the sewage. cost

[0006] Therefore, it is necessary to develop a blast furnace gas scrubbing water scale inhibitor suitable for high salt, high alkalinity, and high hardness to solve the problems of low scale inhibition rate, high operating cost, and damage to water pumps and pipelines due to scaling on pipe walls , so as to ensure the stable operation and normal processing of the blast furnace gas washing water system