Abstract: An aqueous suspension of zeolite NaY is treated in with sodium hydroxide solution. The treated zeolite NaY is subsequently dealuminized with silicon tetrachloride.

Abstract: Gray-black inclusion pigments are made using zirconium silicate as the encasing substance and carbon black particles as the inclusion phase by annealing a mixture of zirconium dioxide, a source for silicon dioxide, carbon black and mineralizers under reducing conditions at 900.degree.-1400.degree. C. The process uses zeolites with an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of more than 4, preferably more than 10, as the SiO.sub.2 source. The depth of the color can be increased by also using an adhesion agent, especially silicon oil. The use of the zeolites facilities the employment of different zirconium dioxide qualities and permits the production of pigments with higher carbon black inclusion rates.

Abstract: Coated spinel color pigments with a core of a colored spinel, in particular CoAl.sub.2 O.sub.4, and a coating glassy layer of a silicate are described. The coating layer is essentially silicon dioxide and one or more oxides of the group of alkali metals, alkaline earth metals, and/or earth metals show a high resistance to bleeding in the presence of glass fluxes, as compared to uncoated spinels. The pigments are produced by sintering, for 0.5 to 5 hours, a powder mixture of the spinel, silicon dioxide, and at least one member chosen from the group of alkali metal halides, alkaline earth metal halides, earth metal halides and mixtures thereof as mineralizer at 900.degree. to 1,300.degree. C. The coated spinel color pigments are suitable for the production of ceramic decorations with improved contour sharpness.

Abstract: A zeolite catalyst and a method for reduction of nitrogen oxides present in waste gas streams is described. The method includes mixing the waste gas containing nitrogen oxides with ammonia. At an elevated temperature, this mixture is passed over a zeolite catalyst. Preferably, the zeolite catalyst is in a monolithic or honeycomb form. The zeolite catalyst includes one or more of the following subgroup metals: copper, iron, molybdeum and cerium. The zeolite catalysts made in accordance with this invention show better conversion of nitrogen oxides and longer life than known catalysts.

Abstract: The invention relates to new brown to gray inclusion pigments, based on zirconium silicate as casing substance, which are characterized in that they contain mixed crystals of the type (Fe.sub.1-x Mn.sub.x).sub.2 O.sub.3, in which x stands for a number in the range from 0.05 to 0.60, as colored compounds. The production takes place by means of annealing a mixture of SiO.sub.2 and ZrO.sub.2, or of precursors, in the presence of iron compounds and manganese compounds, in an Fe/Mn atomic ratio of 90:10 to 20:80, and mineralizers at 750.degree. to 1200.degree. C. The brown pigments are formed especially at temperatures of 850.degree. to 1000.degree. C. and if x is between 0.05 and 0.20. The gray pigments are formed especially at 1050.degree. to 1200.degree. C. and if x is 0.30 to 0.60.

Abstract: Beige-brown encapsulated pigments are obtained by means of the encapsulation of iron titanates of the formula Fe.sub.2 TiO.sub.5 in zirconium silicate crystals. The production takes place by calcining a mixture of zirconium oxide with a particle size distribution of .ltoreq.5 .mu.m and specific surfaces of .gtoreq.4 m.sup.2 /g, silicon dioxide and iron oxides and titanium oxides or oxide-forming Fe compounds and Ti compounds in the presence of mineralizers under oxidizing conditions at 800.degree. to 1300.degree. C.

Abstract: The preparation of gray-green unitary pigment bodies based on zirconium silicate-vanadium oxide wherein a mixture of zirconium oxide and silicon oxide in the presence of a vanadium and lithium compound is calcined above 600.degree. C. and wherein the amount of V.sub.2 O.sub.5 is more than 17 percent by weight and the amount of lithium compound added is such that the atom ratio Li/Li+V is from 0.1 to 0.5.

Abstract: Gray-black pigments are prepared by encapsulating iron titanates of formula FeTiO.sub.3 in zirconium silicate crystals. Manufacture is by calcining a mixture of zirconium oxide having a particle size distribution of 6 to 10 .mu.m and a specific surface area of 2 to 5.2 m.sup.2 /g, silicon dioxide and iron and titanium oxides or Fe and Ti compounds forming oxides in the presence of mineralizers under oxidizing conditions at 800 to 1300.degree. C. Finely divided FeTiO.sub.3 can also be used.

Abstract: The grayish-black encapsulated pigments contain carbon black particles with specific surface areas of 10 to 1000 m.sup.2 /g (BET) encapsulated in colorless crystals of zirconium silicate. In order to produce the pigments, mixtures of zirconium oxide with a particle size distribution (D50 values) between 7 and 10 .mu.m and a spec. surface between 2 and 4 m.sup.2 /g, silicon oxide, carbon black and mineralizers are heated under reducing conditions to 900.degree. to 1400.degree. C. and calcined for 0.5 to 8 hours and recalcined under oxidizing conditions to remove the non-included carbon black. The encapsulated pigments of the invention are suitable for the pigmented coloration of glazes.

Abstract: There are described blue luminescent glasses having the following compositions(a) 0 to 90 mole % alkali metal oxide (sodium oxide, potassium oxide, lithium oxide), individually or several together, 0 to 90 mole % alkaline earth metal oxide (magnesium oxide, calcium oxide, strontium oxide, barium oxide), individually or several together, with the proviso that the magnesium oxide and/or calcium oxide can only be present in an amount of up to 25 mole % and at least 2 mole % of alkali metal oxide and/or alkaline earth metal oxide must be present(b)7 to 95 mole % silica0 to 70 mole % boron oxide (B.sub.2 O.sub.3)0 to 85 mole % aluminum oxide(c) 0.01 to 40 mole % lead oxide (PbO).

Abstract: Encapsulation pigments comprising chromophoric particles embedded in glaze-stable casings are prepared by means of calcination from the appropriate initial products. High yields and strong color intensities are obtained if the chromophoric substance or its initial compounds are bound in and/or to a zeolite and are calcined in this form with the remaining constituents.

Abstract: There are described luminescent glasses having the following compositions(a) 0 to 80 mole % alkali metal oxide (sodium oxide, potassium oxide, lithium oxide), individually or several together, 0 to 30 mole % alkaline earth metal oxide (magnesium oxide, calcium oxide, strontium oxide, barium oxide), individually or several together, and at least 2 mole % of alkali metal oxide and/or alkaline earth metal oxide must be present(b)7 to 90 mole % silica1 to 50 mole % boron oxide (B.sub.2 O.sub.3)1 to 30 mole % aluminum oxide(c)0.1 to 5 mole % lead oxide (PbO)0.1 to 10 mole % vandium pentoxide (V.sub.2 O.sub.5).The glasses have white, yellow, or blue luminescence, depending on the PbO and V.sub.2 O.sub.5 content, at excitation with a wave length of 254 nm.

Abstract: There are described luminescent materials based on zinc silicate activated with manganese which are not sensitive to impurities are not susceptible to pulverizing, are temperature stable, and are stable to the customary ceramic glazes. They comprise, consist of (or consist essentially of):1.5 to 94.8 mole % zinc oxide (ZnO)1 to 90 mole % Silicon dioxide (SiO.sub.2)0.2 to 1.3 mole % Manganese oxide (MnO)0.1 to 25 mole % Alkali oxide and/or Alkaline earth oxide and/or Titanium oxide (TiO.sub.2) and/or Zirconium oxide (ZrO.sub.2) and/or Chromium oxide (Cr.sub.2 O.sub.3) and/or Lead oxide (PbO)0.1 to 23.8 mole % Sodium oxide (Na.sub.2 O)1.3 to 24 mole % Aluminum oxide (Al.sub.2 O.sub.3) and2.5 to 48 mole % Silicon dioxide (SiO.sub.2).

Abstract: There are prepared luminescent materials based on cadmium borate activated with manganese which is insensitive to impurities, temperature stable, not sensitive to grinding, and stable to ceramic glazes having the composition. In the preparation, the manganese activator is added in the form of a zeolite.

Abstract: There are described luminescent materials activated with lead upon excitation with long wave and short wave ultraviolet rays emit in the blue-green region, have long afterglow times, can be prepared from components which do not have high purity, are not susceptible to pulverizing, and are stable to the customary ceramic glazes. They consist of (or consist essentially of):10 to 89.9 mole % zirconium oxide (ZrO.sub.2)5 to 85 mole % boron oxide (B.sub.2 O.sub.3)5 to 85 mole % silicon dioxide (SiO.sub.2)0.1 to 20 mole % lead oxide (PbO)0 to 15 mole % sodium oxide (Na.sub.2 O)0 to 15 mole % potassium oxide (K.sub.2 O) and0 to 5 mole % aluminum oxide (Al.sub.2 O.sub.3).