A process for producing alumina, the process having a seeding phase and a precipitation phase. During the seeding phase a seed mixture is produced by adding an aluminium salt to an aqueous solution and then adding an alkaline metal aluminate to the mixture while maintaining the seed mixture at generally neutral pH. The precipitation phase produces precipitated alumina by simultaneously adding aluminium salt and alkaline metal aluminate to the seed mixture while maintaining a pH from 6.9 to 7.8. The recovered precipitated alumina has at least one, preferably all the following characteristics: i) a crystallite size of 33-42 Ang.: in the (120) diagonal plane (using XRD).; ii) a crystallite d-spacing (020) of between 6.30-6.59 Ang.; iii) a high porosity with an average pore diameter of 115-166 Ang.; iv) a relatively low bulk density of 250-350 kg/m.sup.3; v) a surface area after calcination for 24 hours at 1100 C. of 60-80 m.sup.2/g; and vi) a pore volume after calcination for one hour at 1000 C. 0.8-1.1 m.sup.3/g.

A process for producing alumina, the process having a seeding phase and a precipitation phase. During the seeding phase a seed mixture is produced by adding an aluminium salt to an aqueous solution and then adding an alkaline metal aluminate to the mixture while maintaining the seed mixture at generally neutral pH. The precipitation phase produces precipitated alumina by simultaneously adding aluminium salt and alkaline metal aluminate to the seed mixture while maintaining a pH from 6.9 to 7.8. The recovered precipitated alumina has at least one, preferably all the following characteristics: i) a crystallite size of 33-42 Ang.: in the (120) diagonal plane (using XRD).; ii) a crystallite d-spacing (020) of between 6.30-6.59 Ang.; iii) a high porosity with an average pore diameter of 115-166 Ang.; iv) a relatively low bulk density of 250-350 kg/m.sup.3; v) a surface area after calcination for 24 hours at 1100 C. of 60-80 m.sup.2/g; and vi) a pore volume after calcination for one hour at 1000 C. 0.8-1.1 m.sup.3/g.

The invention provides methods and compositions for improving dewatering of mineral slurry. The method comprises adding an R-Succinic Compound (such as octadecenyl succinic acid, hexadecenyl succinic acid, and/or dodecenyl succinic acid) to the slurry. The R-Succinic Compound removes water that would otherwise be trapped within the filtered slurry cake.

The invention provides methods and compositions for improving dewatering of mineral slurry. The method comprises adding an R-Succinic Compound (such as octadecenyl succinic acid, hexadecenyl succinic acid, and/or dodecenyl succinic acid) to the slurry. The R-Succinic Compound removes water that would otherwise be trapped within the filtered slurry cake.

A process for the preparation of an alumina in the form of beads with a sulphur content in the range 0.001% to 1% by weight and a sodium content in the range 0.001% to 1% by weight with respect to the total mass of said beads is described, said beads being prepared by shaping an alumina gel having a high dispersibility by drop coagulation. The alumina gel is itself prepared using a specific precipitation preparation process in order to obtain at least 40% by weight of alumina with respect to the total quantity of alumina formed at the end of the gel preparation process right from the first precipitation step, the quantity of alumina formed at the end of the first precipitation step possibly even reaching 100%. The invention also concerns the use of alumina beads as a catalyst support in a catalytic reforming process.

Nanoplatelet forms of metal hydroxide and metal oxide are provided, as well as methods for preparing same. The nanoplatelets are suitable for use as fire retardants and as agents for chemical or biological decontamination.

This invention is directed to regeneration of solutions comprising metal ions, and production of valuable hydroxide compounds. Specifically, the invention is related to regeneration of spent electrolyte solutions comprising metal ions (e.g. Al ions), such as electrolyte solutions used in metal/air batteries. The invention is further related to production of layered double hydroxides, and, optionally aluminum tri-hydroxide from aluminate.

This invention relates to the regeneration of spent alkaline solutions, for example, alkaline electrolyte solutions used in metal/air batteries, specifically in aluminum/air batteries. The invention provides methods and systems to regenerate alkaline electrolyte solutions by adding water and optionally other solvents to spent electrolyte solutions, thus precipitating metal hydroxides from the spent electrolyte solution.

The present teachings are directed to inorganic oxide materials that include Al.sub.2O.sub.3, CeO.sub.2, and at least one of MgO and Pr.sub.6O.sub.11. The present teachings are also directed to catalysts having at least one noble metal supported on these inorganic oxide materials, as well as methods for treating exhaust gases from internal combustion engines using such catalysts.

A method for treatment of an industrial effluent with aluminum, comprising: the effluent to be treated is carried to a first zone constituted by a tank having a pH of less than 9.5, so as to promote precipitation of the aluminum in aluminum hydroxide form and to facilitate its removal; a second zone is available and the recirculation of a part of a medium located in the zone 1 to the zone 2 and then return to the zone 1, and the injection of gaseous CO.sub.2 into the recirculated medium, are arranged; the solid particles formed in the zone 1 are separated and discharged; wherein in view of the recirculation of the medium where CO.sub.2 has been injected, the amount of dissolved CO.sub.2 available in the zone 1 is 0.5 to 3 times greater than the requirement necessary for the precipitation of the incoming effluent.