Customized Development And Pilot Production Demonstration Of High Efficiency Compound Dispersant For Coal Water Slurry

Due to the special energy structure in China,coal occupies the dominant position of the energy consumption structure in China.As one of the four coal chemical demonstration zones in China,Ordos City in Inner Mongolia contains rich coal resources.However,the traditional way of using coal brings serious environmental pollution.Promoting efficient and clean utilization of coal has become a realistic choice in China.CWS,as a way of efficient and clean utilization of coal,has been widely used in modern coal chemical enterprises.CWS is made of pulverized coal,water and dispersant through special processing technology.Dispersant is a necessary raw material for the preparation of coal water slurry.The main role of chemical dispersant is to change the surface properties of pulverized coal particles,to promote the uniform dispersion of pulverized coal in water,reduce the viscosity of CWS,and then form a good flow slurry.Single dispersants such as naphthalene dispersant,polycarboxylic acid dispersant,melamine dispersant and lignin dispersant were prepared.The pulping performance of single dispersant was compared through the pulping experiment.The higher the pulping concentration of CWS,the better the pulping performance of dispersant was when the pulping viscosity met the national standard.The pulping performance of naphthalene dispersant,polycarboxylic acid dispersant and melamine dispersant is better than that of lignin dispersant under the condition of the same coal and water agent.When the slurry concentration is 62%,it still maintains good fluidity and the fluidity level is above B+.In addition,a single dispersant was used to improve the slurry performance of CWS.Because the preparation method of lignin dispersant and naphthalene dispersant is the same,chemical compound can be used to compound the dispersant,and the chemical compound dispersant can be used to test the pulping performance.The experimental results show that the pulping performance of the chemical compound dispersant is obviously better than that of the single dispersant.When the pulping concentration reaches 62%,the viscosity of the pulping is 732c P and the fluidity grade is A.In this paper,the single dispersant was not only chemically mixed,but also physically mixed.The physical mixture of lignin dispersant with naphthalene dispersant,polycarboxylic acid dispersant and melamine dispersant was carried out respectively.Specifically,the optimal mixing ratio of single dispersant was selected based on the pulping performance of CWS by changing the adding ratio of single dispersant under the condition of keeping the total adding amount unchanged.According to the physical compound pulping experiment,the compound ratio of the best pulping performance can be obtained.The optimal mixing ratio of naphthene dispersant and lignin dispersant is 6:4.At this time,the slurry concentration of CWS prepared is 62.57%,the slurry viscosity of CWS is 406.67c P,and the fluidity level is A.When the optimal mixing ratio of polycarboxylic acid dispersant and lignin dispersant is 4:6,the slurry concentration of CWS is 62.78%,the slurry viscosity is890.67c P,and the fluidity grade is A-.When the optimal mixing ratio of melamine dispersant and lignin dispersant is 6:4,the slurry concentration,slurry viscosity and fluidity grade of CWS are 62.78%,618.33c P and A.In this paper,through the screening of single dispersant,naphthalene series dispersant with less raw materials and simple preparation conditions was selected as the preferred dispersant for pilot test production.Therefore,the preparation conditions of naphthalene dispersants were optimized,and the optimized preparation conditions were applied to the pilot production process.The pilot production experimental base is located in the small and medium-sized enterprise entrepreneurship base of Ejinhoro Banner,Ordos City,Inner Mongolia.As of April 19,2021,this pilot production line has produced nearly 60t of naphthalene dispersants,and pulping experiments have been conducted between the naphthalene dispersants prepared in the pilot experiment and those prepared in the laboratory.Through the comparison of slurry forming performance,the slurry viscosity of CWS produced by Naphthalene series dispersant in the pilot test at the same concentration is not much different from that produced by laboratory Naphthalene series dispersant,and the fluidity level is the same.At last,the slurry performance of naphthalene dispersants was compared with those used by chemical plant 1,chemical plant 2 and chemical plant 3.The experimental results show that under the same conditions,the pulping performance of naphthalene dispersant is obviously better than that of coal water slurry dispersant used in modern coal chemical enterprises.After investigation,the concentration of CWS produced by A chemical group 1 Industry is 59%,60%by A chemical plant 2and 60%by chemical plant 3.In the laboratory,using naphthalene dispersant in the same type of coal and water pulping,the highest pulping concentration of CWS was62%,64%and 64%respectively.It is well known that the increase of slurry concentration is helpful to improve the economic benefit of enterprises.This paper mainly analyzes the economic benefit of the increase of pulp concentration.Using high efficiency compound dispersant,each percentage point increase in the slurry concentration of CWS increases by one percentage point,the coal consumption decreases by 10.91Kg/1000Nm~3,the oxygen consumption decreases by 9.27Nm~3/1000Nm~3,and the effective gas volume increases by 4242.23 Nm~3/h.After calculated,it can bring the economic benefit of 27 million yuan for the enterprise.