Abstract: An aqueous composition for conditioning an aqueous system, for example a sewage slurry, comprises an alkaline earth metal hydroxide, e.g. lime, and an anionic oligomeric polyelectrolyte, e.g. a salt of polyacrylic acid which composition has at least 40% by weight of particulate solid materials. Other components may include a weighting agent, e.g. calcium carbonate, a cationic flocculant, e.g. a polyacrylamide, and a base such as sodium hydroxide.

Abstract: A method of processing waste material comprises treating the material with flue dust and bonding it to form a solid mass with cement powder, e.g. Portland cement. Acidic liquors containing heavy metals can be processed. Suitable flue dust is obtained from cement manufacture.

Abstract: An already existing conventional lime production plant using a rotary kiln discharging directly into a rotary cooler, is converted reversibly to the production of dry hydrated lime by introducing water into contact with the lime in the cooler sufficient to hydrate the lime without requiring any significant change in the operating parameters of the lime production such as material throughput, cooling and combustion air supply rates and firing conditions.

Abstract: According to the present invention we provide a method of controlling the heavy metal content of the water in an aqueous system which comprises incorporating in the system an amount of gamma dicalcium silicate to insolubilize heavy metals present.

Abstract: Producing polymer dispersions for use in papermaking with a relatively high content of a solubilized polymeric material which serves in the presence of paper filler as binder and dissolves only with difficulty, by continuously passing an aqueous suspension of the particulate binder through a treatment zone (2,3,4) in at least part of which it is subjected to shear, the rate of flow and degree of shear being such that the residence time in the zone allows optimum swelling of the binder and the resulting solution of polymeric binder is visually homogeneous. Flocculant and filler are preferably also incorporated to provide a continuous supply of preflocculated filler for a papermaking furnish. Typical materials are cold water soluble starch as binder, polyacrylamide as flocculant and chalk whiting as filler.

Abstract: A composition for flocculating filler in aqueous suspension for use in papermaking, comprising a starch, an organic polyelectrolyte capable of flocculating mineral filler particles in aqueous suspension, and at least one agent capable of regulating the mobility of a dispersion, particularly a substance moderating flocculation of suspended filler or a substance moderating the viscosity of the dispersion.

Abstract: According to the present invention a static mixer comprises a passage for the flow therethrough of a liquid or a suspension of particulate solid in a liquid, said passage having in the direction of flow a lengthwise divergent portion followed by a lengthwise convergent portion. An inlet for fluent material to be mixed with the suspension may converge with and project into the divergent portion. Cement and coal slurry may be mixed in this apparatus.