The invention provides for a method of producing a modified alumina for use in a coating composition, the method being characterised by hydrothermally treating an alumina suspension under specific conditions before and/or after adding an organic modifier. The invention further provides for a modified alumina made according to the method of the invention and to uses of the modified alumina in coating applications including anti-corrosive compositions and adhesive coatings.

The invention provides for a method of producing a modified alumina for use in a coating composition, the method being characterised by hydrothermally treating an alumina suspension under specific conditions before and/or after adding an organic modifier. The invention further provides for a modified alumina made according to the method of the invention and to uses of the modified alumina in coating applications including anti-corrosive compositions and adhesive coatings.

Disclosed is an accuracy compensation method for discharge caustic alkali concentration measuring device in evaporation process, comprising following steps: step 1. collecting process data of instrument values and laboratory values of alkali liquor diopter, temperature and caustic alkali concentration in the evaporation process; step 2. performing sliding average filtering, time series matching and normalization on the process data collected in step 1 to obtain preprocessed process data; step 3. inputting the preprocessed process data into an accuracy compensation model of the caustic alkali concentration measuring device to obtain compensation values; step 4. adding the compensation values of the caustic alkali concentration to the instrument values to realize on-line compensation of the caustic alkali concentration. The disclosed can accurately compensate the concentration value measured by the on-line instrument, and the compensated concentration value can follow the actual change trend; moreover, the measurement accuracy can meet the needs of actual production.

The invention relates to a process for the production of silicon and alumina Aluminium is contacted with a molten slag of a calcium oxide and SiO.sub.2 under conditions facilitating an aluminothermic reaction, thereby forming silicon and an aluminate slag in two phases which are separated. The aluminate slag is converted to alumina and calcium oxide, which is re-fed in the reaction. The aluminium is provided by melting of aluminium scrap or a combination of different aluminium alloys at a temperature of 700 to 1000° C. The primary aluminium melt is adjusted to a content of 8 to 14% of silicon and then cooled to below 660° C., whereby precipitates are formed, and high purity aluminium is obtained to be introduced into the reaction.

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.

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.

A Bayer process increases oxalate removal in the red side of the Bayer process and at least substantially minimises, for example by at least substantially suppressing, precipitation of oxalates in the white side of the Bayer process.

A novel alumina gel is described having an elevated dispersibility index, and in particular a dispersibility index greater than 70%, a crystallite size between 1 and 35 nm, and a sulphur content between 0.001% and 2% by weight, and a sodium content between 0.001% and 2% by weight, the weight percentages being expressed in relation to the total mass of alumina gel. The present invention also discloses the method for preparing said gel comprising at least one step of precipitating at least one aluminium salt, at least one step of heating the suspension obtained and a final heat treatment step for forming the alumina gel.

The present invention relates to the field of solid materials for adsorption of lithium. In particular, the present invention relates to a novel method for preparing a crystallized and shaped solid material, preferably as extrudates, of formula LiX.sub.x.2Al(OH).sub.3, nH.sub.2O with n being comprised between 0.01 and 10, x being equal to 1 when X is an anion selected from among chloride, hydroxide and nitrate anions, and x being equal to 0.5 when X is an anion selected from among sulfate and carbonate anions, comprising a step a) for precipitation of boehmite under specific temperature and pH conditions, at least one shaping step, preferably by extrusion, said method also comprising a final hydrothermal treatment step, the whole giving the possibility of increasing the adsorption capacity for lithium as well as the adsorption kinetics of the materials obtained as compared with the materials of the prior art when the latter is used in a method for extracting the lithium from saline solutions.