The invention relates to a method for producing solid particles from an inorganic solid containing at least one alkali metal and/or alkaline earth metal, comprising at least the following steps: a) providing the inorganic solid containing at least one alkali metal and/or alkaline earth metal; b) extracting the at least one alkali metal and/or alkaline earth metal from the inorganic solid containing alkali metal and/or alkaline earth metal to obtain an extract containing the alkali metal and/or alkaline earth metal and an alkali metal-depleted and/or alkaline earth metal-depleted residue; c) separating the extract from the residue; d) processing the residue to obtain the solid particles, wherein at least one of the processing steps is selected from a group comprising transporting, filling, packaging, washing, drying, adjusting the pH value, separating according to a mean grain size and/or mass and/or density, adjusting a mean grain size, magnetic separating, calcining, thermal rounding and surface coating.

The present invention relates to a process for the preparation of an aqueous suspension comprising at least one calcium carbonate-comprising material, the calcium carbonate-comprising material having a ratio of particles having an average particle size d.sub.80 value to particles having an average particle size d.sub.20 value [d.sub.80/d.sub.20] in the range from 1.5 to 4 and the use of the calcium carbonate-comprising material in paper and board applications, in cosmetics, in caulks and sealants, in adhesives, in paints and coatings, in fibre applications, in plastics applications or for the replacement of PCC in general.

High SRI cementitious systems comprising integral concrete coloring admixtures, toppings, dry-shake hardeners, and other cementitious systems are provided. The high-SRI cementitious systems comprise one or more IR reflective pigments and other components to make-up the cementitious system, depending on the application. The high-SRI cementitious systems of the invention may be in the form of mixtures which increase the total solar reflectivity (TSR or albedo) and the Solar Reflectance Index (SRI) of concrete. The high-SRI cementitious systems may be toppings mixed with water for application to existing concrete surfaces, dry-shake hardeners for application to freshly-placed plastic concrete, or the IR reflective pigments may be mixed into integrally colored concrete in various forms, such as conventional cast-in-place concrete, lightweight concrete, pervious concrete and concrete building panels, pavers or masonry units.

A composite oxide black pigment has characteristics to absorb visible rays and near infrared rays, and is composed of an oxide of main constituent metals including copper, manganese and iron. In a wavelength region of 400 to 1,000 nm, the composite oxide black pigment has a minimum wavelength, at which a transmittance becomes minimum, in a wavelength region of 600 to 800 nm, a molar ratio of manganese/iron is 3/1 to 30/1, and a molar ratio of copper/(manganese+iron) is 1/2 to 1.2/2. Its sole use makes it possible to obtain a transparent vivid bluish, neutral gray color, and also to maximize an absorption in a near infrared region. It is, therefore, excellent in near infrared absorption characteristics.

To provide a heat-ray shielding film and a method for manufacturing the same, capable of exhibiting excellent optical characteristics and high weather resistance, mainly composed of polyvinyl acetal resin and using composite tungsten oxide fine particles with high heat-ray shielding effect, the method comprising: a first step of obtaining a dispersion liquid by dispersing composite tungsten oxide fine particles expressed by a general formula MyWOz and having a hexagonal crystal structure, and dispersing a dispersant into an organic solvent with a boiling point of 120 deg C. or less; a second step of obtaining a mixture by mixing metal carboxylate into the dispersion liquid obtained by the first step; and a third step of drying the mixture obtained by the second step to thereby obtain a heat-ray shielding fine particle-containing composition, and setting a content of the organic solvent remained in the heat-ray shielding fine particle-containing composition to 5 mass % or less.

The present invention provides a method that enables production of a surface-treated colored inorganic particle with which the desired color tone can be consistently reproduced as intended with no variation occurring in the color tone of the compositions produced with the particle, within each production and over multiple production runs. The invention relates to a method for producing a surface-treated colored inorganic particle, comprising spray drying a mixture of a dispersion [I] and a solution [II], wherein the dispersion [I] is a dispersion of inorganic particles having an average particle diameter of 0.005 to 5 μm dispersed in a solvent with a pigment, and the solution [II] is a solution of a surface treatment agent hydrolyzed in the presence of a hydrolysis aid.

The present invention relates to an improved process for producing iron oxide red pigments by the Penniman process using nitrate (also referred to as nitrate process or direct red process).

It is an object of the present disclosure to provide a method for inexpensively producing a high-performance barium sulfate powder which is obtained by using inexpensive barium sulfide as a raw material, has a high whiteness degree, and can suppress the generation of volatile components.

A method for producing a barium sulfate powder comprising a step of heat treating a raw barium sulfate powders obtained by using barium sulfide as a raw material at 600 to 1300° C., wherein a retention time X (minutes) at a heat treatment temperature of t ° C. is more than time expressed by the following general formula:

X (minutes)=A×10.sup.6×e.sup.(−0.015×t)

A is 8 or more, and an upper limit of X is 3000 minutes in the formula.

A paint composition, which comprises a stanchion-encapsulated pigment such as titanium dioxide, can provide enhanced paint quality with reduced cost.

The present invention relates to iron oxide red pigments having improved color values, a process for producing these improved iron oxide red pigments by the Penniman red process using nitrate (also referred to as nitrate process or direct red process) and an apparatus for the production thereof.