Study On Prediction Model Of Slurry Concentration Of Low-rank Coal And Anionic Sulfonate Dispersants

The low-rank coal is rich in reserves but poor in slurry performance.Anionic sulfonate dispersants are cheap and widely used in the field of slurrying.The matching study between low-rank coal and dispersant is one of the important directions to improve the concentration of low-rank coal slurry.With the same condition of coal particle size distribution and pulping process in this thesis,six low-rank coals(Shenhua non-caking coal(SHNC),Lijiahao coal(LJHC),Shenhua long flame coal(SHYC),Wanli coal(WLC),Baoji coal(BJC)and Buertai coal(BETC))and four commonly used anionic sulfonate dispersants(lignin-based dispersant(SLS),naphthalene-based dispersant(NSF),humic-acid-based dispersant(SHS)and aliphatic-based dispersant(SAF))were used for slurry preparation experiments to obtain constant-viscosity concentration.The quantitative method of establishing a prediction model is used to study the mathematical relationship between the constant-viscosity concentration of low-rank coal and the factors of coal quality or the hydrophilic and hydrophobic groups of dispersants.It can reduce the time consumed by traditional slurry preparation experiments and provide a new direction for the selection and design of dispersant.The slurry experiment shows that the constant-viscosity concentration of each low-rank coal is generally higher when it is slurried with NSF,and the constantviscosity concentration is generally lower when it is slurried with SHS.When the lowrank coal is slurried with SLS,the water separation rate is generally smaller and the slurry is stable.When it is slurried with SAF,the water separation rate is generally larger and the stability is poor.With the proximate analysis,ultimate analysis,and infrared spectrum analysis of low-rank coal,the relevant coal quality characteristic data were obtained:moisture(Mad),ash(Ad),volatile matter(Vdaf),fixed carbon(FCd),O/C value and oxygencontaining functional group peak area ratio C=O/C-O value.The single factor and Spearman correlation analysis were carried out between the constant-viscosity concentration and coal quality factors.The results show that Mad,Vdaf,O/C value,and C=O/C-O value in coal quality characteristics are negatively correlated with the constant-viscosity concentration,while Ad and FCd are positively correlated with the constant-viscosity concentration.The coal quality characteristic factors with a strong correlation or higher(the Spearman correlation coefficient is larger than 0.6)are Mad(X1),Vdaf(X2),O/C value(X3),and C=O/C-O value(X4).Combined with the Origin software,the partial least squares(PLS)method was used to perform regression fitting between the constant-viscosity concentration(yi)and the selected coal quality characteristic factors,and the prediction model of slurry concentration based on the influence of coal quality factors was obtained:ySLS=67.635-0.962x1+0.848x2+17.414x3-178.107x4yNSF=74.580-0.564x1+0.731x2+24.901x3-206.441x4ySHS=88.901+0.214s1+0.0129x2+17.265x3-172.670x4ySAF=71.266-0.391x1+0.711x2+10.574x3-181.095x4Taking Baoji coal(BJC)as the research object,the infrared spectrum analysis of four dispersants shows that the molecular structure of anionic sulfonate dispersants mainly includes hydrophilic groups(-OH(X1),-C=O(X2),-C-O(X3)and-SO3-(X4))and hydrophobic groups(-CH3(X5),-CH2(X6)and-C=C(X7)).Further infrared peak fitting was performed to obtain the absorption peak area ratio of the relevant hydrophilic and hydrophobic groups.The Spearman correlation analysis was performed between the constant-viscosity concentration of BJC and the peak area ratio of each hydrophilic and hydrophobic group.The results showed that the groups-OH,-C-O,-SO3-and-CH2 in the dispersant molecule are positively correlated with the constant-viscosity concentration of BJC coal water slurry.The groups-C=O,-CH3,and-C=C in the dispersant molecule are negatively correlated with the constant-viscosity concentration of BJC coal water slurry.Combined with the Origin software,the PLS method was used to perform regression fitting between the constant-viscosity concentration(y)of BJC and the infrared absorption peak area ratio of hydrophilic and hydrophobic groups of dispersants,and the prediction model of slurry concentration based on the influence of different anionic sulfonate dispersants groups was obtained:y=65.201+0.001x1-0.145x2+0.073x3+0.430x4-0.089x5+0.096x6-0.020x7...