Use of additives containing primary alkanolamines in aqueous mineral suspensions
AssigneeOmya International AG
InventorsMatthias Buri, Samuel Rentsch, Fabio Ippolito
Life of this patent
Estimating the term…
Abstract
The present invention relates to the technical domain of additives for aqueous high solids suspensions of mineral materials. The inventive additive comprises specific primary amines and is used for increasing the pH-value of the suspension and/or for increasing the wettability of the mineral materials.
Claims22
An aqueous suspension including an additive comprising a primary alkanolamine, the aqueous suspension containing 48 to 84 wt.-%, based on the total weight of the suspension, of at least one mineral material for increasing the suspension pH by at least 0.3 pH units and/or for increasing the wettability of the at least one mineral material in the suspension,
- wherein the at least one mineral material has a density of 2.0 to 3.0 g/cm3;
- wherein the primary alkanolamine has at most 4 carbon atoms, has a surface tension of 30 to 40 mN/m at 23° C., has a melting point of less than 5° C. and a boiling point of less than 163° C.,
- wherein the suspension contains at least one polycarboxylate dispersant in an amount of 0.1 to 1.5 wt.-%, based on the dry mineral material and
- wherein the primary alkanolamine is added in an amount of from 200 to 10 000 mg per kg of the aqueous phase of said suspension and
- wherein the weight ratio of primary alkanolamine to polycarboxylate dispersant is from 1:2 to 1:25, yielding a suspension pH of 8.0 to 11.5.
A method for increasing the pH of an aqueous suspension containing 48 to 84 wt.-%, based on the total weight of the suspension, of at least one mineral material characterised in that the method involves the step of adding a liquid additive comprising a primary alkanolamine to the suspension in an amount of from 200 to 10 000 mg, per kg of the aqueous phase of said suspension, so that the pH of the suspension is increased by at least 0.3 pH units yielding a suspension pH of 8.0 to 11.5, wherein the at least one mineral material has a density of 2.0 to 3.0 g/cm3 and wherein the primary alkanolamine has at most 4 carbon atoms, has a surface tension of 30 to 40 mN/m at 23° C., has a melting point of less than 5° C. and a boiling point of less than 163° C. and wherein the suspension contains at least one polycarboxylate dispersant in an amount of 0.1 to 1.5 wt.-%, based on the dry mineral material.
A method for increasing the wettability of at least one mineral material in an aqueous suspension containing 48 to 84 wt.-%, based on the total weight of the suspension, of the at least one mineral material characterised in that the method involves the step of adding a liquid additive comprising a primary alkanolamine to the suspension in an amount of from 200 to 10 000 mg, per kg of the aqueous phase of said suspension, wherein the at least one mineral material has a density of 2.0 to 3.0 g/cm3 and wherein the primary alkanolamine has at most 4 carbon atoms, has a surface tension of 30 to 40 mN/m at 23° ° C., has a melting point of less than 5° C. and a boiling point of less than 163° C. and wherein the suspension contains at least one polycarboxylate dispersant in an amount of 0.1 to 1.5 wt.-%, based on the dry mineral material.
Dependencies are inferred from the claim text.