Abstract: An improved process for economically and effectively granulating solid, finely-divided, particulate feedstock comprising phosphogypsum, limestone, or mixtures comprising sulfogypsum, natural or mineral gypsum, or mixtures thereof and limestone and having from about 80 to 95 percent by weight of such sulfogypsum/mineral gypsum to effect products which exhibit excellent physical and chemical properties relative to dustiness, storage, handling, and perhaps most importantly, aqueous media-induced rapidity of reversion to a mesh-size distribution of particles substantially similar to the initial size distribution of said feedstock, which improved process involves introducing such relatively finely-divided feedstock, together with material comprising recycle thereof into a suitable agglomeration device, such as a rotary drum, and therein effecting agglomeration/granulation of such feedstock in the presence of aqueous media, the improvement comprising the utilization, in combination with said aqueous media, of relat

Abstract: An improved process for more economically and effectively producing crystalline by-product ammonium sulfate (A/S) by granulating crystalline by-product A/S feedstock and recycle material together with an A/S-sulfuric acid-granulation aid-particle hardener solution and ammonia to bind the crystals together. Underlying the gist of the improvement concept is the identification of a low-cost readily available lignosulfonate by-product of the pulp and paper industry which, when used in predetermined and relatively small proportions, has now been discovered to be very satisfactory as a granulation aid-particle hardener for granulating such by-product ammonium sulfate crystals. Use of lignosulfonate instead of alum, as is currently practiced, reduces the manufacturing cost of granulating by-product ammonium sulfate by about as much as one dollar per short ton of product.

Abstract: A process for granulating crystalline by-product ammonium sulfate, hereinafter referred to, for the sake of convenience, as A/S, to produce a product having excellent physical and chemical properties as they relate to the storage and handling thereof and also as they relate to the bulk blending of same with other fertilizer blend materials. The method involves introducing the crystalline by-product A/S feedstock, together with recycle material, into a conventional drum ammoniator granulator and granulating the mixture using A/S-sulfuric acid-alum solution and gaseous anhydrous ammonia to bind the crystals together by virtue of the fresh A/S produced and precipitated. Drying in a rotary drum dryer by countercurrent flow of hot gases instead of the more conventional cocurrent gas flow is required.

Abstract: The present invention teaches a simple method for reclaiming principally the N and S values in by-product, fine, crystalline ammonium sulfate in a granular form eminently suitable for the preparation of direct application fertilizers and/or the incorporation into bulk-blending operations for the preparation thereof.In the instant invention, normally from about seventy (70) percent to about eighty (80) percent of the ammonium sulfate product produced therefrom, is derived from feedstock comprising said by-product, fine, crystalline ammonium sulfate. Furthermore, in one embodiment for the practice of the instant invention, from about eighty (80) percent to about eighty-eight (88) percent of said fine, crystalline ammonium sulfate feedstock is directly incorporated thereinto with the remainder thereof being indirectly introduced thereinto by means of applicants' prepared special "binder.

Abstract: A process for granulating finely divided particulate sulfate or chloride salts of potassium to produce therefrom agricultural products having exceptionally satisfactory physical and chemical properties in regard to bulk blending with other fertilizer blend materials and also in regard to storage and handling properties. The instant methods involve introducing fine-sized, particulate feedstock together with recycle material into a conventional granulator and granulating the solids with use of a water solution comprised of the potassium salt to be granulated and portions of lignosulfonate, which solution has been found to bind the solids material together in a manner and form highly desirable. Drying of the resulting granulation material is required. Nominal grades of the sulfate and chloride granular products are about 47 and 57 percent by weight K.sub.2 O equivalent, respectively.