Study on pulping performance of a novel coal water slurry additive for Shenhua coal slurry with high concentration
Shenhua coal is difficult to form slurry of high concentration, low viscosity for its strong hydrophilicity. Based on that, coal water slurry (CWS) additive, denoted as LS-A, was used to prepare Shenhua coal blending slurry with high concentration, and then the slurry ability, rheological characteristic and static stability of LS-A were investigated. The results show that, the performances of CWS were improved by LS-A, and it had good viscosity reducing effect. The slurry concentration could reach 65.5%, and the apparent viscosity is smaller than 1200 MPa·s with good flow property under 100 s-1 of shearing rate when the dosage of LS-A was 0.7%. The rheological investigation indicated that the slurry pumped with LS-A is pseudoplastic fluid, and it had rheological property of shear-thinning, evident thixotropic property and good stability. Moreover, the comparison of pulping properties and stability between LS-A and the additive SPHF-3 of National CWS Center showed that, the slurry ability was similar under same additive dosage.
A METHOD FOR OPTIMIZING COAL SLURRYING PROPERTY
An orthogonal experiment was conducted in laboratory to investigate the Shenhua coal water slurrying property.The regression equation was obtained by multi-factor regression and variance analysis,and the optimal additives ratio and particle size distribution were gained through a computer program optimization method.The results show that the optimization method can raise solid concentration of the Shenhua coal water slurry,and the concentration is increased from 59.51% to 62.36%.Furthermore,the stability and rheology of the coal water slurry are also improved after particle size gradation.
Viscosity of suspensions of spherical and other isodimensional particles in liquids
The viscosity of a suspension is related to the properties of the suspending liquid and the suspended particles by measuring the viscosity of suspensions made up of closely sized materials such as glass spheres, plastic Zeolite spheres, blasting sand, and salt cubes in a wide range of concentrations in liquids of varying properties made up of castor oil, tetrabromoethane and carbon tetrachloride, or corn syrup and water. The measurements were made under carefully controlled conditions by means of a Brookfield viscometer, and the reproducibility of results was demonstrated by repetitive runs. 
 
Equations are derived to describe the viscosities of these various suspensions in terms of the viscosity and density of the suspending liquid and of the shape, size distribution, density, and concentration of solid particles. The range of concentration covered is from infinite dilution to near infinite viscosity. 
 
The results obtained can best be explained by postulating nonuniform distribution of particles in a suspension in a network of tetrahedral and simple cubical packings.