Method for the production of iron oxide pigments
(57) Abstract:The invention relates to the technology of production of iron oxide pigments used as colorants. The invention consists in the following: at the stage of separation and washing of red mud from alkali alumina production from the zone of deposition or seal the last washer select small fraction of red mud required size (for example, using a siphon) and then it is filtered. The precipitate collected on the filter, washed, dried, calcined and get finished products of iron oxide pigment. The method allows the use of as raw material, in contrast to the method known, not thickened red mud with its subsequent dilution with water for sustainable operation of hydrocyclones for selection of the required fraction of red mud, and the intermediate slurry zone of the last (tail) washer red mud, precluding the use of hydrocyclones in the scheme and the dilution of the sludge water. 1 Il. The invention can be used to obtain the dyes of iron oxide pigments from red mud (waste from alumina production). A method of obtaining iron oxide pigment thermal JV is Lesny sulphate dehydrate prior to the formation of monohydride iron sulfate and then calcined at 700-825oC prior to the formation of iron oxide:
FeSO47H2O FeSO4H2O + 6H2O,
2FeSO4H2O ---> Fe2O3+ SO3+ SO2+ 2H2O
The disadvantage of this method is its complexity and high cost: first, dehydrating liquid sulphate is the sintering of particles, which reduces the quality of the pigment, so after dehydration, the product is subjected to grinding; secondly, the annealing of iron sulphate in rotary kilns is a long process (up to a residual content of iron sulfate in the product 5 - 10%), which increases the cost method.As a prototype accept the method of obtaining iron oxide pigments (RF patent N 2047631, C 09 C 1/24, 1995 /2/) from red mud waste from alumina production. The method involves the separation of the red mud by class size in the hydrocyclone with a sampling fraction of particles not larger than 0.02 mm and calcination of this fraction at 290 - 850oC.The disadvantage of this method is that, first, for the stable operation of hydrocyclones need thinning red mud water up to 6 m3water per 1 ton of sludge, i.e. the imbalance in water: second additional spending for the maintenance and operation of hydro determines the complexity of the method and reduces its effectiveness.The purpose of the invention is improving the efficiency of the method.The technical result - the possibility of selecting the necessary fraction of red mud for the production of iron oxide pigment without the use of hydrocyclones.The technical result is achieved in that in the method of production of iron oxide pigments from red mud, including how and the way-prototype , the selection of the fraction of red mud required size, filtering the selected fraction and annealing, fractional sampling of the red sludge carried from the zone of deposition or seal the last washer on the stage of separation and washing of red mud from alumina production.The drawing shows a diagram of the production of iron oxide pigment according to the proposed method.The scheme includes the latest (usually 4th or 5th) washer 1 red mud from alumina production, for example, 5-tier washer, as shown in the drawing, the mixer with pump 3 with the direction of selected fractions by filtering, washing, drying and calcination.The method is as follows. At the stage of separation and washing of red mud from the alkali in the alkaline method of production of alumina and is Prosti. Selection, in particular, can be carried out with the upper tier of the washer with a mark of mirror solution 1,0 - 1,25 m Selected fraction through the mixer 2 by the pump 3 is directed to filtering. Obtained filter cake is subjected to washing, drying and calcination, for example, in the crucible of the furnace, and receive the finished products of iron oxide pigment.The selection of red mud is the last of the washer, as in this case provides better washing of the sludge from the alkali (compared with cuttings taken from the first or intermediate washer).The fundamental difference between the proposed method from the prototype method in the following: use not waste alumina production - thickened red mud, and the intermediate slurry zone of the washer, so you do not need thinning red mud water in the process of selecting its fractions; eliminates the use of hydrocyclones.The advantages of the proposed method, due to the presence of distinctive features: no additional equipment is hydrocyclones and, as a consequence, no additional costs for maintenance (release drain pipes from crusts); the absence of RA the Nations red mud, which faction + 0,063 mm does not exceed 0.2%, while the hydrocyclone she reaches 2.0%; on the other hand, you can obtain the fraction of red mud in other industries, for example, for the production of brick, concrete, varying the depth and the radius of the sampling point of the red sludge from the tail washer; proposed sampling scheme with red mud allows, in contrast to the prototype method, to obtain an almost unlimited number of iron oxide pigments (up to 600 thousand tons of pigments in the year). Method for the production of iron oxide pigments from red mud, including the selection of the fraction of red mud required size, filtering the selected fraction and annealing, characterized in that the fractional selection of red sludge carried from the zone of deposition or seal the last washer red mud at the stage of separation and washing of red mud from alumina production.
FIELD: varnish-and-paint industry.
SUBSTANCE: invention is intended for use in chemical industry and construction for preparing varnishes, paints, and rubber products. Gas treatment slime from converter industry is fractioned, fraction up to 10 mm is dehydrated by drying at 70-110°C to at most 5% moisture content and reduced to particles not exceeding 300 μm in size. Color spectrum of product is extended from red to black by calcining disintegrated product at 300 to 900°C. Content of iron oxides in pigment is much higher than in pigments prepared using known processes.
EFFECT: widened resource of raw materials, utilized converter industry waste, and reduced price of product.
2 cl, 1 tbl, 6 ex
FIELD: metallurgy; building industry; varnish and paint industry.
SUBSTANCE: the invention is pertaining to the field of metallurgy, building industry, varnish and paint industry, in particular, to the method of production of a red ferrioxide pigment. A ball mill is charged with industrial water, loaded with iron oxide with concentration of 500-900 g/dm3, poured with a neutralizing agent in the amount ensuring pH 6 ÷ 10. The iron oxide is formed at a thermal decomposition of the hydrochloride solutions used at etching treatment of carbon steels. As a neutralizing agent it is possible to use caustic soda, a slaked lime, microcalcite. The suspension is pulped for 3-5 hours, put in a reactor with a stirrer, where it is washed out with formation of a suspension, filtered off and dried. The target product has the following parameters: pH 5 ÷ 8; the share of water-soluble salts - 0.02-0.03 %; dispersing ability - 27-30 microns; hiding power - 6 ÷7 g/m2. The invention allows to simplify process and to upgrade parameters of the pigment.
EFFECT: the invention allows to simplify process and to upgrade parameters of the pigment.
2 cl, 1 tbl, 1 ex
FIELD: paint-and-varnish industry; construction engineering; painting plastics and leather; production of enamel paints, primers, putties, wall-paper and veneer.
SUBSTANCE: solution of hydraulic washing-out of used melt of titanium chlorates containing ferrous chloride (II) is treated with alkaline reagent to pH= 2.5-4.5 at precipitation of oxyhydrates of metals. Solution is separated from sediment by filtration. Cleaned solution thus obtained is mixed with solution obtained after leaching-out of copper-containing melt of process of cleaning titanium tetrachloride from vanadium compounds by means of copper powder. Ratio of volumes of said solutions is 1 : (0.5-2), respectively. Mixed solution is treated with alkaline reagent to pH= 9-11. Suspension thus obtained is subjected to filtering. Sediment is washed, dried and calcined additionally at temperature of 400-700°C. Proposed method makes it possible to utilize wastes of process of production of titanium dioxide from titanium tetrachloride. Pigment thus obtained has rich black color, reflection coefficient of 3.5±0.5%, hiding power of 4.5±0.5 g/m2 and pH of aqueous suspension of 7.0±0.5.
EFFECT: enhanced efficiency.
2 cl, 1 ex
FIELD: pigment technologies.
SUBSTANCE: invention is intended for use in varnish-and-paint industry and in rubber and plastics production. Red iron oxide pigment preparation comprises: oxidation of aqueous solutions of ferric sulfate or suspensions of ferric hydroxide with air oxygen at quasi stationary temperature and pH values of reaction medium; hydrothermal heat treatment of suspension of ferric oxyhydroxides in periodical or continuous regimes in autoclaves; washing-out of pigment from water-soluble salts; drying and grinding of the pigment. During hydrothermal heat treatment FeOOH suspension is affected by nanosecond electromagnetic pulses having following characteristics: pulse duration 0.5-5 ns, pulse amplitude 4-10 kv, pulse repetition frequency 200-1000 Hz. Process is carried out at 130-200°С.
EFFECT: lowered FeOOH suspension hydrothermal heat treatment temperature and increased pigment preparation productivity.
1 tbl, 12 ex
FIELD: chemical and paint-and-varnish industries; production of inorganic pigments.
SUBSTANCE: proposed method includes leaching-out of serpentine ore mixture containing magnesium and chromium by sulfuric or hydrochloric acid for obtaining iron-containing solution which is treated with hydrogen peroxide and is neutralized to pH= 7.0-8.0. Suspension thus obtained is filtered and iron hydroxide residue is dissolved with sulfuric or hydrochloric acid, then it is treated with alkaline reagent to pH=2.0-6.0 and is filtered. Then, iron hydroxide residue is washed off water-soluble ions, dried and burnt at temperature of 550-700C.
EFFECT: wide range of tints in processing and decontamination of sulfate and chloride waste obtained at production of periclase and chromite concentrate.
2 cl, 5 tbl, 6 ex
FIELD: chemical industry; metallurgy industry; other industries; methods of production of the high purity ferric oxides.
SUBSTANCE: the invention is pertaining to the method of production of the high purity ferric oxides and may be used in production of the pigments and the catalysts at production of the high purity ferric oxides. The ferric oxides are produced by interaction of the metallic iron made in the form of the microball-shaped particles either the scrap, or the turning chips, which dimensions are such, that the area of their surface per one kg of iron and per one liter of the reaction medium makes more than 0.01 m2 with the being stirred water solution of the carboxylic acid having рКа from 0.5 up to 6 for the first carboxyl and capable to thermolysis in the open air at the temperature of from 200 up to 350°С into carbon dioxide and the water. The ratio between the moles of the carboxylic acid and g-atoms of the iron makes from 0.03 up to 1.5 and the mass ratio of the water/iron - from 1 up to 20, the microball-shaped particles are kept in the suspension by stirring. The produced carboxylate of the ferrum (II) is oxidized up to carboxylate of the ferrum (III) with the oxidant selected from oxygen, the oxygen-containing gaseous mixture and hydrogen dioxide. The earlier produced carboxylate of the ferrum (II) also may be exposed to the oxidizing. Then the carboxylate of the ferrum (III) is heated up in the open air till production of the oxides. The invention allows to increase the purity of the ferric oxides and productivity at their production.
EFFECT: the invention ensures the increased purity of the produced ferric oxides and productivity at their production.
9 cl, 12 ex
SUBSTANCE: present invention pertains to production of black iron oxide pigments and can be used in paint and coating industry. The black iron oxide pigment is obtained from burning red mud - aluminous production waste. Before burning, the red mud is sorted according to size, with selection of the 0.02 mm fraction and further selection of the 0.02-0.045 mm fraction. These fractions are burnt in a controlled atmosphere with oxygen deficiency at 500-1000°C temperature.
EFFECT: obtaining iron oxide pigment of a pure black colour with 8-10 g/m2 coverage using aluminous production wastes - red mud, without more raw materials and additives and pollution of the environment.
SUBSTANCE: natural mechanically milled iron (III) oxide of lamellar structure at least 50 wt %, preferentially 75 wt %, contains particles sized 10 mcm and less in amount, at least, 50 wt %, preferentially 70 wt %, particularly preferentially 90 wt %. The ratio of thickness to maximum diametre of iron (III) oxide plates is 1:5, preferentially 1:10. To produce such iron (III) oxide, it is mechanically milled in an impactor or a jet-type mill. Iron (III) oxide resulted from mechanical milling, is separated by size grade, e.g. by an air separator. Iron (III) oxide can be used in lacquering for a base corrosion protection, mechanical load protection, UV and IR protection, for decorative coating, and also as an extender for polymeric and ceramic materials.
EFFECT: possibility to prepare highly dispersed lamellar particles of natural iron oxide.
SUBSTANCE: method for preparation of iron oxide pigment from specularite includes specularite milling up to particle size more than 1 mm - 5 mm, after material concentration with magnetic separation up to content of α-Fe2O3 more than 60.0 wt % specularite is concentrated again. Concentrated specularite can serve as starting material for obtaining of pigment with dull luster consisting of iron mica with Fe2O3 content more than 85 wt % which includes thin scaly plates in amount more than 50 wt % and is featured with residue after wet sieving on a sieve with mesh size 63 mcm not more than 35 wt %.
EFFECT: invention allows to obtain pigments from specularite for protective-decorative and decorative coatings.
8 cl, 2 tbl, 5 ex
SUBSTANCE: invention relates to protection of metals from corrosion using lacquer coatings. The engineering problem is solved using a method of preparing an anticorrosion pigment based on aspiration dust wastes from foundry electric furnaces. The aspiration dust is mixed with calcium hydroxide in water with content of calcium hydroxide in the mixture with aspiration dust equal to 8-11 wt %, and aspiration dust with calcium hydroxide in water is taken in ratio of 1:1 respectively. The obtained mixture is dried, calcined at 820-900°C for 3.5-5.5 hours and then ground up to the required degree of dispersion.
EFFECT: possibility of simplifying preparation of a highly efficient anticorrosion pigment and without presence of toxic components in it, as well as reduction of cost of the pigment and environmental conservation.
1 cl, 2 tbl, 15 ex