Abstract: A process for treating thickened phosphatic clay suspensions produced in the processing of phosphate ore by water beneficiation, and which have a solids content of from about 5% to about 30%. A deflocculating agent is mixed with the suspension to cause deflocculation of the suspension to an extent sufficient to reduce the viscosity of the sludge to a value enabling the deflocculated suspension to be readily pumped from one location to another. The deflocculated suspension is subsequently mixed with an additive compound comprising an alkaline earth metal oxide or hydroxide in an amount sufficient to cause the formation of large silicate molecules with resultant gelling and setting of the sludge into an inert solid material.

Abstract: A process for separating suspended clay and sand solids from the slimes of phosphate tailings is described. The suspended solids are rapidly agglomerated and a relatively dense sludge which settles to the bottom of the separation vessel is formed. The sludge may then be discharged into settling ponds for dewatering and compaction.

Abstract: The invention relates to a method of processing the waste sludge obtained in purification facilities for phosphoric acid produced by the wet process. The composition of this sludge is such that it cannot be utilized for any purpose in this state. It is known that sludge from wet phosphoric acid purification facilities contains different quantities of certain substances, the concentrations being such that these substances may not be allowed to mix with surface water or ground water under any circumstances, not even in the case of dumps. A typical composition of such waste sludge is as follows:______________________________________ Fe 9.0% by weight P.sub.2 O.sub.5 21.0% by weight CaO 6.2% by weight SiO.sub.2 12.5% by weight MgO 5.8% by weight Al.sub.2 O.sub.3 2.7% by weight Cr.sub.2 O.sub.3 0.7% by weight V.sub.2 O.sub.5 0.6% by weight Na.sub.2 O 18.0% by weight K.sub.2 O 0.3% by weight F 1.7% by weight C 2.5% by weight S 0.3% by weight Remainder* 18.7% by weight 100.

Abstract: Removal of phosphates from waste water can be attained with improved efficiency and at low cost by admixing the waste water with seawater and adjusting the mixture to pH 9-11 to separate the sedimental phosphates. The sediment can be utilized as phosphatic fertilizer.

Abstract: Use of an effective amount of a precipitant or sequestrant for calcium ions improves performance of anionic polymeric carboxylic acid flocculants in flocculating phosphate slimes.