摘要:
The invention relates to a process for making granulated, partially or completely hydrated alkali metal diphosphates or triphosphates. To this end, the invention provides for alkali metal diphosphates or triphosphates which consist to an extent of at least 20% of particles with a size of less than 0.045 mm and are hydrated to an extent of less than 90%, based on the phosphates' theoretical content of water of hydration, to be intensively mixed and granulated in the presence of water and an ammonium polyphosphate, this latter being used in a proportion of about 0.5 to 50 weight %, based on the quantity of water used.
摘要:
The invention relates to a process for making phosphorus-containing anticorrosive pigments having a size of at most 20 microns by reacting one or more compounds of magnesium, calcium, strontium, barium, zinc, aluminum, iron, chromium or manganese with an oxygen acid of phosphorus or its alkali metal or ammonium salts at temperatures within the range 10.degree. to 100.degree. C. More particularly pigments consisting to an extent of at least 90% of particles with a size between 0.05 and 8 microns are produced by introducing an aqueous suspension or solution of the reactants into a dispersing means rotating at a speed of 3000 to 10,000 rpm, reacting the reactants by intimately mixing them, and separating and drying precipitated pigment.
摘要:
The invention relates to a process for making a finely dispersed, sparingly soluble salt of an oxyacid of phosphorus, having a maximum particle size of 20 .mu.m, by reacting a compound of a divalent metal with the oxyacid of phosphorus or an alkali metal or ammonium salt thereof. More particularly, finely dispersed salt consisting to an extent of at least 90% of particles with a size between 0.05 and 7 .mu.m is made. To this end, an at least 5% by weight aqueous solution or suspension of a compound of a divalent metal selected from the group Mg, Ca, Sr, Ba, Mn, Zn, Cu, Cd, Pb, Sn, Co and Ni is reacted, while maintaining a pH range of between 3 and 9 and while stirring, with an at least 2 mol % solution of at least one trivalent metal selected from the group Al, Fe and Cr in the oxyacid of phosphorus and, optionally, with an aqueous solution of an alkali metal or ammonium salt of the oxyacid of phosphorus, and the precipitated salt is separated off and dried.
摘要:
The invention relates to the production of phosphorus-containing anticorrosive pigments with a particle size of at most 20 microns by reacting one or more calcium or magnesium compounds with phosphoric acid or acid alkali metal or ammonium phosphates by intimately mixing an aqueous suspension or solution of the reactants inside a dispersing means rotating at a speed of 3000 to 10,000 rpm. More particularly, fine pulverulent calcium and magnesium compounds are converted, with agitation, together with water and, if desired, a water-soluble alkanol to a homogeneous suspension or solution. The suspension or solution is intimately mixed, inside the dispersing means at 0.degree. to 40.degree. C. and in an approximately stoichiometric ratio, with the phosphoric acid or acid phosphate solution. Resulting and precipitated pigment is separated and dried under mild conditions while maintaining its content of water of crystallization. The anticorrosive pigment is comprised of a homogeneous mixture and/or mixed crystals of which 10 to 95 mol % is calcium hydrogen phosphate dihydrate, the balance being magnesium hydrogen phosphate trihydrate. An at least 55 weight % proportion consists of particles with a size of up to 5 microns with a BET-surface of at least 1 m.sup.2 /g.
摘要:
The invention relates to a process for converting water-soluble, condensed phosphates of the following general formula (I)M.sub.2 O(MPO.sub.3).sub.n (I)in which M stands for sodium, potassium or ammonium and n stands for a number between 4 and about 100, to granulate, wherein the pulverulent, water-soluble, condensed phosphate is thoroughly agitated and granulated in the presence of water and of a phosphate salt other than the condensed phosphate. More specifically, the condensed phosphate of general formula (I) or a mixture of the phosphate with an anhydrous or partially hydrated alkali metal phosphate is thoroughly agitated and granulated in the presence of water and an ammonium polyphosphate of the following general formula (II)H.sub.(n-m)+2 (NH.sub.4).sub.m P.sub.n O.sub.3n+1 (II)in which n stands for an integral average value of 3 to 1000, m stands for a whole number of up to n+2, and the m/n-ratio is between about 1.0 and 1.67.
摘要:
The disclosure provides a process for making mixed granulates from water-soluble condensed phosphates and at least one builder salt by subjecting the components making the granulate to granulation in the presence of water. To this end, the disclosure provides:(a) for water to be sprayed on to a mixture of the condensed phosphate, the builder salt and an ammonium polyphosphate as a binder, and for the mixture to be granulated, or(b) for an aqueous solution or suspension of ammonium polyphosphate to be sprayed on to the mixture of condensed phosphate and builder salt, and for the mixture to be granulated.
摘要:
The disclosure relates to a process for making granulated, hydrated alkali metal orthophosphates. To this end, the disclosure provides for one or more anhydrous or partially hydrated alkali metal orthophosphates presenting a degree of hydration of less than 90%, based on the theoretically possible degree of hydration, and containing an at least 20% proportion of particles with a size of less than 0.045 mm, to be intensively mixed and granulated with water and an ammonium polyphosphate.
摘要:
The disclosure relates to a granulate with a particle size essentially of about 0.2 to 2 mm consisting of(a) about 2 to 95 weight % of a partially or completely hydrated pentasodium tripolyphosphate,(b) less than 3 weight % of an ammonium polyphosphate and the balance(c) being in the form of a water-insoluble aluminum silicate ion exchanging material.The granulate can be used in detergents.
摘要:
Pure Maddrell salt is produced by heating sodium phosphate to temperatures of 250.degree. to 420.degree. C. The sodium phospate used as starting material is sodium trimetaphosphate or a mixture of sodium trimetaphosphate with Maddrell salt, monosodium orthophosphate or disodium pyrophosphate, the mixture containing Na and P in a molar ratio of 1:1. Prior to heating the starting material, it is admixed with 0.5 to 5 weight% of orthophosphoric acid, polyphosphoric acid, phosphorus pentoxide or at least one salt of a volatile base forming polyphosphoric acid at the temperatures specified. The resulting mixture is calcined over the period necessary to transform the starting material to Maddrell salt.
摘要:
To prepare essentially water-insoluble, chain-form ammonium polyphosphate from equimolar amounts of di- ammonium phosphate and phosphorus pentoxide in the presence of ammonia at temperatures of from 170.degree. to 350.degree. C. with constant mixing, kneading and comminution, at least some of the diammonium phosphate and phosphorus pentoxide is replaced by partially ammoniated polyphosphoric acid.A plant for carrying out this process can comprise a sealed reactor (1) which is provided with metering devices (2, 3) and feed tubes (4, 5) for phosphorus pentoxide and diammonium orthophosphate, an ammonia feed tube (8), an ammonium polyphosphate discharge tube (9) and a line for offgas. Rotatable mixing, kneading and comminution elements are provided inside the reactor (1). Furthermore, a heatable stirred tank (11) which can be charged with polyphosphoric acid via a feed line (13) is provided and can be used to remore water vapor and ammonia from the offgas flowing from the reactor (1) via the line (20) and from which partially ammoniated polyphosphoric acid can be introduced into the reactor (1) via an outlet line (17).