An abrasive particle having a body including a first major surface, a second major surface opposite the first major surface, and a side surface extending between the first major surface and the second major surface, such that a majority of the side surface comprises a plurality of microridges.

The rate of release of a well treatment agent into a well may be controlled by introducing into the well a screen containing a well treatment composite having a well treatment agent and a support for the well treatment agent. The diameter of the substrate is less than the diameter of the opening of the screen of the screen assembly. Over time, the well treatment agent is released from the substrate and passes from the interior of the screen into the well.

A glass ceramic substrate includes: an inner layer part having a first thermal expansion coefficient; and a surface layer part having a second thermal expansion coefficient smaller than the first thermal expansion coefficient. The inner layer part contains a first glass matrix and flat alumina particles. The flat alumina particles are dispersed in the glass matrix in a direction in which individual thickness directions are substantially perpendicular to a surface direction of one of main surfaces of the inner layer part. Further, a mean aspect ratio of the flat alumina particles is 3 or more in one of cross sections along the thickness directions of the flat alumina particles out of cross sections of the inner layer part.

A supported catalyst having a calcined, predominantly aluminium, oxide support and an active phase of 5 to 65% by weight nickel with respect to the total mass of the catalyst, said active phase having no group VIB metal, the nickel particles having a diameter less than or equal to 20 nm, said catalyst having a mesopore median diameter greater than or equal to 14 nm, a mesopore volume measured by mercury porosimetry greater than or equal to 0.45 mL/g, a total pore volume measured by mercury porosimetry greater than or equal to 0.45 mL/g, a macropore volume less than 5% of the total pore volume, said catalyst being in the form of grains having an average diameter comprised between 0.5 and 10 mm. The invention also relates to the process for the preparation of said catalyst and the use thereof in a hydrogenation process.

There is provided a process for purifying aluminum ions comprising: reacting an aluminum-containing material with an acid so as to obtain a composition comprising aluminum ions; precipitating said aluminum ions in the form of AlCl.sub.3; optionally converting AlCl.sub.3 into Al(OH).sub.3; and heating said AlCl.sub.3 or said Al(OH).sub.3 under conditions effective for converting AlCl.sub.3 or Al(OH).sub.3 into Al.sub.2O.sub.3 and optionally recovering gaseous HCl so-produced. Aluminum ions so purified are thus useful for preparing various types of alumina.

A process of forming a sintered article includes heating a green portion of a tape of polycrystalline ceramic and/or minerals in organic binder at a binder removal zone to a temperature sufficient to pyrolyze the binder; horizontally conveying the portion of tape with organic binder removed from the binder removal zone to a sintering zone; and sintering polycrystalline ceramic and/or minerals of the portion of tape at the sintering zone, wherein the tape simultaneously extends through the removal and sintering zones.

A method for preparing high purity alumina (HPA) is provided. The method includes subjecting an aluminum feedstock to acid leaching, thereby yielding an aluminum bearing leachate; subjecting the aluminum bearing leachate to solvent extraction, thereby yielding an organic phase which is loaded with aluminum; stripping the aluminum from the loaded organic phase with a stripping solution containing an acid, thereby yielding an aluminum bearing extract; crystallizing an aluminum salt from the aluminum bearing extract; dissolving the aluminum salt in an ammoniacal solution, thereby generating a boehmite precursor compound and an ammonium salt; calcining the boehmite precursor compound to yield HPA; subjecting the ammonium salt to electro-dialysis, thereby yielding ammonia and the acid; and performing at least one step of (a) utilizing the ammonia in preparing the ammoniacal solution used in a subsequent iteration of the method, or (b) utilizing the acid in preparing the stripping solution used in a subsequent iteration of the method.

The catalytic cracking catalyst contains a molecular sieve and an alumina substrate material. The alumina substrate material has a crystalline phase structure of γ-alumina. Based on the volume of pores with a diameter of 2-100 nm, the pore volume of the pores with a diameter of 2-5 nm accounts for 0-10%, the pore volume of the pores with a diameter of more than 5 nm and not more than 10 nm accounts for 10-25%, and the pore volume of the pores with a diameter of more than 10 nm and not more than 100 nm accounts for 65-90%.

A strontium-catalyzed process for preparing boehmite includes combining a strontium material, flash calcined gibbsite, and water to obtain an aqueous suspension; contacting the aqueous suspension with a water-soluble carbonate material; and heating the aqueous suspension to a temperature, and for a time, sufficient to form at least about 5 wt. % of boehmite.

A method for preparing aluminum fluoride and aluminum oxide by decarburization and sodium removal of an aluminum electrolysis carbon residue is disclosed. The method includes: crushing the aluminum electrolysis carbon residue into fine particles not larger than 3 mm, adding decarburization agent into the carbon residue, mixing to obtain first mixture, adding the first mixture into a high-temperature furnace, conducting I-stage heating treatment in air atmosphere to obtain crude fluoride salt A; adding sodium removal agent into the crude fluoride salt A, mixing to obtain second mixture, adding the second mixture into high-temperature furnace, and conducting

II-stage heating treatment to obtain crude fluoride salt B; adding the crude fluoride salt B into stirring tank, adding industrial pure water, dissolving a sodium salt into water, and conducting solid-liquid separation to obtain precipitate C and sodium salt solution D; drying the precipitate C to obtain aluminum fluoride and aluminum oxide.