Synthesis And Properties Of Sulphonated Humic Acid Department CWS Dispersants

Oil shortages are the most serious energy crisis currently, China is a coal-producing country, because of the low utilization of coal resources, waste and pollution problem are the most prominent issues, haze phenomenonin recent years are caused by pollution. So take the oil problem seriously and efficient use of coal resources have become a social problem need to be solved. CWS as a new type of clean and efficient energy alternatives to oil, has been paid more and more attention.As the core of CWS technology, dispersants determines its performance.The main role of the dispersant is to reduce the viscosity of coal-water slurry and increase the stability of CWS. In this paper, it choose the inexpensive natural humic acid macromolecules, and modified by introducing hydrophilic group and increasing the relative molecular mass to synthesize two sulfonated humic acid dispersant, respectively sulfonated humic acid-formaldehyde-sulfonated acetone polycondensate and sulfonated humic acid-sulfonated acetone-urea-formalde hyde polycondensate. It analyzed their structure by FT-IR, DSC, TG, contact angle, zeta potential, rheology, and the new humic acid-based CWS dispersants were synthesized as expected. Compare them with sulfonated humic acid and commercially available naphthalene dispersant, we study the superiority and inferiority.First, it use alkali solution and acid extraction to extract the crude humic acid from Shanxi Lingshi, and we study the structure of humic acid and sulfonated humic acid by IR and GPC, the main functional groups of them were measured by acid-based titration, the results showed that the total content of acidic groups in humic acid was 4.402 mmol/g, which the content in sulfonated humic acid was 6.848 mmol/g.The first scheme synthesized a new type of sulfonated humic acid-formaldehyde- sulfonated acetone polycondensate dispersant. It studied the optimum ratio of reactants to develop optimum solutions. The results showed that the optimum molar ratio of humic acid and sodium sulfite was 3:1, and when the temperature was 85 ℃, the sulfonated humic had best performance; the optimum molar ratio of sulfonated humic acid and sulfonated acetone was 2:1, the amount of formaldehyde was 35%, the optimum reaction temperature was 80℃, the optimum time was 3 h.When the content of dispersant was 0.3%, the largest coal-water slurry concentration was 67%, the apparent viscosity of the slurry prepared was 930 m Pa·s. The static adsorption of the dispersant in keeping with the Langmuir isotherm equation, 1g Binchang pulverized coal could adsorb 5.99 mg dispersant. The stability of dispersant was secondary by the measure of water rates.The second scheme synthesized sulfonated humic acid-sulfonated acetone-urea-formaldehyde polycondensate. The best solution for synthesis as follows. The amount of urea, formaldehyde were 28% and 40%, the optimum temperature was 85 ℃, the optimum time was 3h, the amount of other materials as the first scheme.To the dispersants synthesized which had the best performance, the optimum amount of dispersants was 0.25%, the maximum concentration was 68%, the apparent viscosity was 902 m Pa·s. Dispersant SHUA was monolayer adsorption which in keeping with the Langmuir isotherm equation, 1g Binchang pulverized coal could absorb about 7.69 mg SHUA dispersant. Its stability was first-class.Compared with commercially available naphthalene dispersant NSF and sulfonated humic SHS, the two synthesized dispersants had better performance, and worth promotion and application.