Abstract: An apparatus for producing phosphoric acid by the recovery of P.sub.2 O.sub.5 from a phosphate ore is disclosed. A slurry of a phosphate ore in an aqueous phosphoric acid solution is formed in each of a plurality of reaction zones connected in series. Phosphate ore is introduced into the first reaction zone and phosphoric acid into the last reaction zone whereby the reaction of the phosphoric acid with the ore forms a slurry of coarse solids, fine solids and monocalcium phosphate in the phosphoric acid solution. A first process stream comprising coarse solids is removed from the first reaction zone and each of the other reaction zones and is tranferred to the adjacent, successive reaction zone.

Abstract: A process and apparatus for producing phosphoric acid by the recovery of P.sub.2 O.sub.5 from a phosphate ore is disclosed. A slurry of a phosphate ore in an aqueous phosphoric acid solution is formed in each of a plurality of reaction zones connected in series. Phosphate ore is introduced into the first reaction zone and phosphoric acid into the last reaction zone whereby the reaction of the phosphoric acid with the ore forms a slurry of coarse solids, fine solids and monocalcium phosphate in the phosphoric acid solution. A first process stream comprising coarse solids is removed from the first reaction zone and each of the other reaction zones and is transferred to the adjacent, successive reaction zone.

Abstract: Described herein is a process for producing potassium salts from potassium-based liquors for pulping of lignocellulosic material. The process comprises the steps of(a) digesting lignocellulosic material with a potassium-base aqueous cooling liquor to obtain an aqueous slurry of partially delignified pulp of the lignocellulosic material;(b) separating the pulp from the spent potassium-base aqueous cooling liquor;(c) concentrating the spent pulping liquor; and(d) recovering potassium salts including potassium carbonate, potassium sulphate and potassium lignosulphonate from the concentrated spent pulping liquor. The recovered potassium salts find numerous uses, an example being use in fertilizers.

Abstract: This invention relates to an integrated acoustic network system to provide warning of impending groundfall in underground mines. The system includes a plurality of geophones which derive acoustic signals by which the source of seismic disturbances is located, and an array of high frequency piezoelectric sensors which pick up signals from small ground disturbances which precede groundfall. A warning system is provided both at the scene of mining operations and at a central location of impending groundfall and of the location of its occurrence.