Influence of different dispersants on dispersion characteristics of carbonate-containing mixed magnetic concentrates
HAN Huili
XIE Kecheng
ZHAO Yingtai
WANG Yulian
SUN Haoran
ZHANG Zhibin
YUAN Zhigang
Abstract：Objective To improve the separation efficiency of carbonate-containing refractory iron ore and achieve efficient utilization of complex and refractory iron ore resources,the dispersion performance and mechanism of carbonate-containing mixed magnetic concentrate slurry treated with different dispersants are studied,providing a basis for the application of dispersants in refractory ore separation.
Methods The mixed magnetic concentrate from the Dong'anshan Sintering Plant was used as the research object,and a disper-sion experimental device was independently designed.Based on mineral sample analysis,the dispersion effects of small-molecule organic dispersants(citric acid,malic acid,butane tetracarboxylic acid),a large-molecule organic dispersant(sodium carboxymethyl cellulose),and inorganic dispersants(sodium silicate,sodium hexametaphosphate)on the slurry were investigated.The effects of different dispersants on the slurry's dispersibility,turbidity,particle size distribution,and aggrega-tion state were studied,revealing the dispersion mechanism of these dispersants.
Results and Discussion The total iron(TFe)grade of the mixed magnetic concentrate sample was 42.97％.The yield of par-ticles with a particle size smaller than 48 μm in the ore sample was about 84％,of which particles smaller than 23 μm were about 45％.The particle size of Fe was mainly less than 37 μm,with a metal distribution rate of over 80％.Fine particles were prone to mutual adsorption and agglomeration,adhering to the coarse particle surface of useful iron minerals and gangue miner-als,making ore separation difficult.The addition of dispersants enhanced the dispersibility of the mixed magnetic concentrate slurry.The dispersion degree of the slurry treated with the polymer organic dispersant CMC-Na and two inorganic dispersants,sodium hexametaphosphate and sodium silicate,was less than 35％,while the dispersion degree for the three small-molecule dispersants,malic acid,citric acid,and butanetetracarboxylic acid,was greater than 46％,demonstrating stronger dispersion effects.These dispersants also exhibited advantages such as good water solubility,high efficiency,non-toxicity,low cost,and wide availability.When the mass concentration of citric acid,malic acid,and butanetetracarboxylic acid was 440 mg/L,the slurry turbidity reached its maximum values of 1 850,1 900,and 2 000 NTU,respectively.Under the influence of these three small-molecule organic dispersants,a large number of fine particles were restored from an agglomerated state to a single particle state,enabling better dispersion in water and an increase in slurry turbidity.The D50 values of the slurry particles treated with citric acid,malic acid,and butanetetracarboxylic acid were 21.98,20.97,and 19.67 μm,respectively,while the D90 values were 64.73,62.69,and 61.65 μm,respectively.All three dispersants reduced the apparent size of the slurry particles.
Conclusion After adding the three small-molecule organic dispersants-citric acid,malic acid,and butanetetracarboxylic acid-to the slurry,a combined effect of electrostatic repulsion,hydration repulsion,and steric hindrance was induced.This syner-gistic action broke the agglomeration and surface adhesion among fine particles,causing them to transition from an aggregated state to a monodispersed state.As a result,the dispersion and turbidity of the slurry increased while the particle size decreased.
Keywords：magnetic concentratedispersantdispersion characteristicsdispersion degreeturbidityparticle size
Publication Date：2026-03-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：12( 89-100 )