Pennzoil Company

Dysart E Holcomb

John B Sardisco

Louis E Kidwell, Jr

Erhart K Drechsel

Erhart K Drechsel, Deceased

Phosphate rock, including low grade phosphate ore, is treated to recover phosphoric acid and other valuable products by a series of steps including contacting phosphate ore with a weak phosphoric acid to form a suspension of at least a portion of the slimes contained in the ore so that the slimes can be separated from the ore, and separating the slimes to provide a deslimed phosphate ore. Deslimed phosphate rock is solubilized with phosphoric acid to convert at least a portion of the calcium contained in the rock and form a solution of monocalcium phosphate and phosphoric acid. After removal of solids, this solution can be treated with sulfuric acid in a gypsum crystallizer to form gypsum and the phosphoric acid product wherein filterable gypsum crystals are obtained by maintaining a total SO.sub.3 content of 1.5-4 wt. % in a first crystallizer and neutralizing the SO.sub.3 in a second crystallizer. In other aspects of the invention, at least a portion of the phosphoric acid produced may be recycled to convert additional ore and the slime suspension may be treated to recover the weak acid recovered from the suspension. Further, wash water from the gypsum filter may be recycled to the desliming stage, the filtrate from the deslimer may be cycled to the acidulation reactor and monocalcium phosphate may be recovered as a separate product from phosphoric acid and connected to other useful products.

Production of phosphoric acid and additional products from phosphate ore

There is disclosed a method for upgrading of hydrocarbon mixtures, so as to reduce their content of gum precursors such as diolefins and pseudo-diolefins, and provide a resulting product mixture suitable for mild hydrogenation, for use as a motor fuel or as a feed stock to an extraction unit. The process comprises obtaining a hydrocarbon mixture containing about 60-90 wt. % of aromatic components, about 3-40 wt. % of dienes and pseudodienes, and monoolefins, and up to about 6 wt. % of relatively unreactive organic compounds, reacting this mixture with elemental sulfur in the approximate weight ratio of about 5-95 wt. % of the hydrocarbon mixture with about 95-5 wt. % of elemental sulfur, the reaction being carried out at a temperature in the range of 100.degree.-150.degree. C. for about 10 minutes to 24 hours with good mixing, removing the unreacted materials by distillation and separating a sulfur-hydrocarbon reaction product to provide the upgraded hydrocarbon mixture.

Method for upgrading diene-containing hydrocarbon mixtures

Monocalcium phosphate, phosphoric acid and/or potassium phosphate, calcium fluoride and gypsum are produced in a process involving acidulation of phosphate rock with phosphoric acid, and wherein monocalcium phosphate dissolved in phosphoric acid is formed during acidulation. In important features, insolubles and impurities are removed and a portion of the monocalcium phosphate may be separated and recovered. Alkali metal ion is added to the solution to form alkali metal fluosilicate, such as K.sub.2 SiF.sub.6, is separated and hydrolyzed with calcium ion to form CaF.sub.2 and the solution is recycled as RH.sub.2 PO.sub.4 /H.sub.3 PO.sub.4 for further reaction with fluorides, where R is alkali metal. A portion of the MCP/H.sub.3 PO.sub.4 solution and/or crystallized monocalcium phosphate can then be reacted with potassium sulfate, potassium bisulfate, or mixtures thereof, to form KH.sub.2 PO.sub.4 or KH.sub.2 PO.sub.4 /H.sub.3 PO.sub.4 solutions, and gypsum or with H.sub.2 SO.sub.4 to produce phosphoric acid. The remaining monocalcium phosphate/phosphoric acid solution can be reacted with sulfuric acid to produce phosphoric acid product and the recycle phosphoric acid required in the phosphate rock acidulation step.

Preparation of monocalcium phosphate and/or phosphoric acid from

Phosphate is upgraded to remove slimes therefrom by a process which comprises the steps of:

Upgrading of phosphate ore

A novel sulfur-based adduct formed by reacting sulfur with a diene-containing by-product hydrocarbon mixture available from petrochemical operations and/or from coal processing. The adduct is a reaction product of sulfur and each of the dienes contained in the by-product mixture. Also disclosed is a road surface composition containing this adduct as an asphalt extender or as a replacement for asphalt, and there are also disclosed other compositions containing this adduct such as sulfur cements, sulfur concretes, coatings, foams, structural materials and insulators.

Growing community of inventors

Shreveport, LA, United States of America

Dysart E Holcomb