초록 ▼

A process for treating a clay mineral of the kandite group comprising forming a fluid aqueous suspension of the clay mineral, the suspension having a solids content in the range of from 60% to 75% by weight and a pH in the range of from 7.0 to 11.0 and the suspension containing a dispersing agent to

A process for treating a clay mineral of the kandite group comprising forming a fluid aqueous suspension of the clay mineral, the suspension having a solids content in the range of from 60% to 75% by weight and a pH in the range of from 7.0 to 11.0 and the suspension containing a dispersing agent to deflocculate the clay mineral; and treating the fluid suspension of clay containing the dispersing agent with a water-soluble reducing bleaching agent under alkaline pH conditions for a time sufficient to give the desired improvement in brightness of the clay. Preferably, the clay mineral suspension is subjected to a particle size separation process at said solids content to reduce the percentage of particles larger than 10m

대표청구항 ▼

A process for treating a raw kaolinitic clay mineral which comprises forming a fluid aqueous suspension of the kaolinitic clay mineral, said suspension having a solids content in the range of from about 60% to about 75% by weight and a pH in the range of from 7.5 to 10.5 and said suspension containi

A process for treating a raw kaolinitic clay mineral which comprises forming a fluid aqueous suspension of the kaolinitic clay mineral, said suspension having a solids content in the range of from about 60% to about 75% by weight and a pH in the range of from 7.5 to 10.5 and said suspension containing from 0.05 to 0.6% by weight of the dry clay of a dispersing agent system comprising from 2.5 to 7 parts by weight of a water-soluble condensed phosphate to 1 part by weight of a water-soluble organic polymeric dispersing agent; subjecting said suspension to a particle size separation technique at a temperature such that the viscosity thereof is less than 2 poise to reduce the percentage by weight of the particles larger than 10 m3% by weight; and treating said 60% to 75% solids suspension with a water-soluble reducing bleaching agent at an alkaline pH in the range of pH 7.5 to 10.5 for a time sufficient to increase the brightness of the clay mineral, said process being carried out without the necessity for dewatering said suspension.