Processing method of red muds of alumina industry
SUBSTANCE: invention refers to non-ferrous metallurgy, and namely to complex processing of red muds of alumina industry. Processing method of red muds of alumina industry involves obtaining of red mud pulp, extraction and concentration of rich components by combination of classification and magnetic separation methods. After the pulp classification, fine-grain fraction pulp is extracted and subject to vibrocavitation treatment and further magnetic separation with extraction of magnetic and non-magnetic products. At that, magnetic product is subject to additional classification so that iron-bearing and scandium-bearing concentrates are obtained.
EFFECT: increasing the complexity degree of processing of red muds owing to increasing the extraction degree of rich components to target products - scandium-bearing concentrate and iron oxide concentrate.
4 cl, 3 tbl, 1 ex
The invention relates to ferrous metallurgy, namely the complex processing of red mud from alumina production.
There is a method of processing red mud from alumina production, including reductive roasting of red mud in the presence of a reducing agent (coal or toxic) at a temperature of 700-800°C, magnetic separation in a magnetic field 80-100 kA/m sintered material with obtaining iron concentrate and alumosilicates product, which then receive the scandium containing concentrate known methods (sabirianov N.A., S. p. Yatsenko - Chemical methods of complex processing of bauxite - Ekaterinburg, Ural branch of the Russian Academy of Sciences, 2006, pp. 217-218).
The disadvantages of this method are primarily related to the complexity and multi-stage process for the complex processing of red mud, is primarily due to the application at the initial stage of high-temperature firing.
The method for extracting rare earth metals, scandium and yttrium from the red mud of alumina production, which consists in the fact that the red sludge in the form of a slurry with a solid content of 50% share in density in a centrifugal field during acceleration 40-100 m/s, the flow sigalda water 3-10 l/min, with "heavy" and "light" fraction, from which the next method MAGN is based separation in magnetic field strength 400-1600 kA/m extract rare earth concentrate (RF patent 2147622, C22B 59/00, C22B 7/00).
The disadvantages of the method include the following:
- not a high yield of iron concentrate, which have a high content of Fe2O3equal to 65-70%, but the output is only 8-10%;
- low extraction of scandium oxide concentrate (contents ~0,030% or 300 g/t)of ~10%.
The closest to the technological nature, the totality of symptoms and the achieved technical result is a method of processing red mud from alumina production, including extraction and concentration of valuable components methods of classification and magnetic separation (A.S. USSR 1715874, C22B 59/00, C01F 7/02).
The method is as follows.
The original slurry the slurry is subjected to classification according to the class of particle size 40-60 μm, the slurry particle size of less than 40-60 μm (average, 50 µm) and acidified with mineral acids (HCl or H2SO4) to a pH of 1.5-4.0, maintained at the resulting pH and stirring for 10-15 min to break up the agglomerates of mineral particles and then with respect to T:W=1:6 is subjected to magnetic separation in a magnetic field 40-80 kA/m Magnetic product, the output of which is 4.0-7.0 wt.%, is a enriched in oxides of iron and scandium concentrate - Fe2O3and Sc2O3accordingly, in rednam, 70,0% and 0.035%. With an average output of the magnetic concentrate of 5.5 wt.% extraction of valuable components from the original red mud is approximately 18% and 15.5%.
The disadvantage of this method is the low level of comprehensive utilization of red mud, due to the low degree of extraction of valuable components in the target products.
The technical result of the invention is the provision of conditions for enhancing the utilization of red mud, manifested in the increase in the degree of extraction of valuable components - iron oxide and scandium in the target products.
This goal is achieved by a method of processing red mud from alumina production, which includes obtaining a slurry of pulp extraction and concentration of valuable components based on the combination of the classification methods and wet magnetic separation and differs from the previously known method that is allocated when the initial classification of the original slurry of red mud, fine-grained fraction is subjected vibrocavitational processing with subsequent wet magnetic separation at specific values of the magnetic field has been divided into magnetic and non-magnetic products and further additional classification of magnetic product with obtaining, respectively, iron and scandium-containing conc is stratov.
The above set of distinctive features provides the technical result consists in increasing the degree of complexity of processing red mud by increasing the degree of extraction of valuable components - iron oxide and scandium in the target products.
20,0 DM3production of a slurry of red mud containing 6.0 kg of the solid phase composition, wt.% - 43,0 Fe3O3and 0.010 Sc2O3- subjected to sieve classification class a particle size of 50 μm. Lower intermediate - pulp particle size of less than 50 microns, containing 5.2 kg of the solid phase composition, wt.%: 47,0 Fe2O3and 0,012 Sc2O3- processed in vibrocavitational the mixer when the value of the peripheral speed of the rotor mixers ω=50,0 m/s for 20 minutes Then the slurry is directed to magnetic separation in the electromagnetic cassette filter-separator with tension (N) of the magnetic field of 700 kA/m with a separation into magnetic and non-magnetic products with output (η), respectively, and 25,0 75,0%.
Pulp magnetic product containing 1.25 kg of the solid phase (61,4% Fe2O3and 0,018 Sc2O3), and with T:W=1:5, is directed to the classification class a particle size of 20 microns.
The pulp is lower middlings particles smaller than 20 µm - filtered, the precipitate is ushitsa at a temperature of 110-120°C for 2 hours to obtain scandium-containing concentrate, containing 0.040% for Sc2O3; output concentrate 5.0% of the number of initial CABG (fraction - 50 μm).
The product particles larger than 20 microns - is (after filtering and drying) iron concentrate (60,0% Fe2O3with 80.0% of the number of magnetic product and/or 20.0 wt.% on the number of initial CABG (fraction - 50 μm).
Removing iron oxide and scandium in the target products respectively 27.5% and 19%.
In table 1-3 shows the results of experiments on complex processing of red mud in the implementation process according to the claimed invention, and beyond optimum limits.
Table 1 presents the results of the experiments in the implementation process in the optimal mode vibrocavitational processing pulp fine-grained fraction of ceteris paribus in General:
- tension (N) of the magnetic field of 700 kA/m is the Extraction of valuable components regarded end-to-end, i.e. from the content in the original red mud and taking into account the output of the fine-grained fraction (- 50 μm).
|The results of the experiments in the implementation process in the optimal mode vibrocavitational processing sludge slurry ceteris paribus the conditions|
|No. of experiments||Processing options||The output of the magnetic product, %||The content in MP, wt.%||Removing components, %|
|ω, m/s||τ min||Fe2O3||Sc2O3||Fe2O3||Sc2O3|
|when the optimal mode|
|beyond optimum limits|
Thus, as can be seen from table 1, the optimal conditions vibrocavitational processing pulp fine fraction (particle size less than 50 microns), while providing an equal magnetic field strength of 700 kA/m, the achievement of the required technical result, an increase in the degree of increasing the recovery of valuable components - iron oxide and scandium in the target products is significantly higher than in the known method (prototype), are the following (op÷5): the value of the peripheral speed (ω) of the rotor under stirring 50-80 m/s and the processing time of 15-25 minutes
Beyond optimum limits parameters:
- reduce the peripheral speed ω to 40 m/s (up) or treatment duration up to 10 min (op) not only leads to reduction of the yield (η) magnetic product to ~19,0%, but also to a significant decrease of the content in the latest iron oxide up to, on average, ~51,0%, which leads to the reduction of extraction of Fe2O3to ~17.5 per cent, i.e. at the level of values obtained by a known method. This is due to insufficiency fracture of aggregates of iron-containing magnetic particles with him is gnatname particles of minerals "waste rock" (hydroelasticity sodium and hydrogenate calcium);
the increase in the peripheral speed ω to 90 m/s (AP) and/or the duration of treatment 30 min (op) reduces the output of the magnetic product to the ~of 17.0% on average, and hence the extraction of Fe2O2to the value ~of 17.0%, i.e. lower than that in the known method. This is due to pereizlucheniem particles of hematite (Fe2O3) when vibrocavitational processing in super mode, which reduces the value of the magnetic susceptibility of the primary iron-bearing mineral in the red mud.
Table 2 shows the results of carrying out the process in the optimal mode magnetic separation under other equal conditions the initial vibrocavitational processing: the value of the peripheral speed ω=65 m/s and a duration of 20 minutes
|The results of the experiments in the implementation process in the optimal mode magnetic separation ceteris paribus|
|No. of experiments||The magnetic field strength kA/m||The output of the magnetic product, %||Component content, %||Removing the compound is, %|
|when the optimal mode|
|beyond optimum limits|
As can be seen from table 2, the optimal conditions for magnetic separation viboolyavatana sludge slurry for achieving the desired technical result: the increasing complexity of the use of red mud by increasing the degree of extraction of valuable components - iron oxide and scandium in the target products are the values of magnetic field strength (op÷3) 600 to 800 kA/m
When you exit the optimum values of the process of magnetic separation:
for the lower limit is N=500 kA/m (op) observed a decrease in the output of the magnetic product to 16.5%, which leads on the one hand a very low degree of extraction of Fe2O3(weakly magnetic hematite), equal to 17.5%, and a low concentration of the oxide of scandium, equal 0,019%, considerably below the content Sc2O3in the target product by a known method (~0,035%). The latter is associated with nadaswaram at low magnetic field Sc-containing weakly magnetic mineral - chamosite;
the upper limit is N=900 kA/m (op) observed the effect of a significant decrease in the content of valuable components in the magnetic product, especially oxide of scandium - up 0,013% Sc2O3that actually is at the level of content in IP is one fine (particle size less than 50 microns) fraction 0,012%, i.e. the concentration of valuable components, almost none. It is connected with the recovery in the magnetic product with high values of magnetic field strength of the other contained in the red mud of the weakly magnetic minerals, in particular alumalite-glandular hydrogenate containing Fe2O3and Sc2O3accordingly ~25-30% Fe2O3and ~0.005% of Sc2O3that largely razboiul magnetic product.
In table 3 the results of carrying out the process in an optimal manner classification of magnetic product under other equal conditions in the previous process operations: vibrocavitational processing and magnetic separation.
|The results of the experiments in the implementation process in the optimal mode classification ceteris paribus|
|No. of experiments||The class of particles, microns||The output of concentrates, %||Content targeted to those %||Removing the target concentrate, %|
|Fe-content. to-t||Fe2O3in Fe-sod. to the||Sc2O3in MRK||Fe2O3||Sc2O3,|
|when the optimal mode|
|beyond optimum limits|
As can be seen from table 3, the optimal condition classification of magnetic product is the separation of the solid phase, class of particles with sizes in the range of 15-25 μm, (op÷3) resulting in an increase in the degree of extraction of valuable components - iron oxide and scandium - target products, respectively, on average, to 27.0% and 19%.
The output of process parameter classification or lower limit of the particle size (10 μm - op)or upper limit (30 μm - op) leads to a significant reduction in the degree of extraction of scandium oxide in rare metal concentrate to ~11-15%, which is below the value of such values in the known method.
This is due to removing a faction - 10 µm hydroaluminosilicates Na2O·Al2O3·nSiO2contained in the red mud (magnetic product), the particles of which have dimensions of 1÷5 μm, and in the second case (op) is the increase in the output of scandium-containing concentrate to 7.5% by increasing the content of hematite (Fe2O3) - a mineral that does not contain the oxide of scandium, which significantly reduces the soda is the content of the last (to 0.020%) of the target product.
Now, only a process to recycle red mud from alumina production under optimal conditions: fibroepithelioma processing pulp fine-grained fraction, when values of the circumferential speed of 50-80 m/s and duration of 15-25 min, magnetic separation in a magnetic field of 600 to 800 kA/m and classification of magnetic product, class of particles 15-25 min achieve the desired technical result: increased complexity of processing red mud by increasing the degree of extraction of valuable components of the oxides of iron and scandium in the target products (concentrates), respectively, to an average of 27.5% and 19.0%, or increase, in comparison with the known invention (prototype) respectively ~8,5% and 4.0%.
1. A method of processing red mud from alumina production, including extraction and concentration of valuable components by a combination of classification and magnetic separation, characterized in that after the classification of the pulp of the original red mud emit a fine pulp fraction and subjecting it vibrocavitational processing and subsequent magnetic separation with separation of magnetic and non-magnetic products, magnetic product is subjected to additional classification with obtaining, respectively, iron and skindisorders the th concentrates.
2. The method according to claim 1, characterized in that vibrocavitational processing pulp fine-grained fraction of the class of particles of 50 microns is carried out at a circumferential speed under stirring 50-80 m/s and duration of 15-25 minutes
3. The method according to claim 1, characterized in that the magnetic separation of the treated pulp is carried out at a magnetic field strength of 600 to 800 kA/m
4. The method according to claim 1, characterized in that the classification of the pulp magnetic product are class particles 15-25 μm.
SUBSTANCE: proposed method comprises dissolving scandium-bearing concentrate in sulfuric acid, removing acid-insoluble residue, and precipitating scandium in the presence of ammonium compounds. Then, precipitate is filtered, flushed, dried and calcined to obtain scandium oxide precipitate. With acid-insoluble residue removed, sulfuric acid concentration in filtrate is increased to 540-600 g/dm3, ammonium chloride is added to solution in amount of 26.7-53.5 g/dm3 at 50-70°C and held for one hour at mixing. Produced precipitate is flushed by ethanol at volume ratio of 1-10-11.
EFFECT: simplified process, higher purity scandium oxide.
SUBSTANCE: method of extracting yttrium (III) from salt solutions involves floatation extraction using an organic phase and a collector. The organic phase used is isooctyl alcohol. The collector used is an anionic surfactant - sodiium dodecyl suphate in a concentration which corresponds to the stoichiometry: Y+3+SDS-=Y[DS]3, where Y+3 is a yttrium cation, DS- is a dodecyl sulphate ion. Floatation extraction is carried out at pH=7.0-7.8 and ratio of the organic phase to the aqueous phase of 1/20-1/40.
EFFECT: high degree of extraction of yttrium.
2 dwg, 1 ex
SUBSTANCE: invention refers to complex processing method of carbon-silicic black-shale ores, which contain vanadium, uranium, molybdenum and rare-earth elements. The above method involves ore crushing to the particle size of not more than 0.2 mm and two leaching stages. Oxidation sulphuric-acid leaching is performed at atmospheric pressure. Autoclave oxidation sulphuric-acid leaching is performed at the temperature of 130-150°C in presence of oxygen-containing gas and addition of a substance forming nitrogen oxide, as a catalyst of oxygen oxidation. Ion-exchange sorption of uranium, molybdenum, vanadium and rare-earth elements is performed from the obtained product solution.
EFFECT: increasing extraction degree of vanadium, uranium, molybdenum; improving the complexity of ore use owing to associated extraction of rare-earth elements.
18 cl, 1 dwg
SUBSTANCE: invention relates to the technology of producing compounds of rare-earth elements during complex processing of apatites, particularly extraction of rare-earth elements from phosphogypsum. The method involves preparation of pulp from phosphogypsum and sorption of rare-earth elements on a sorbent. The pulp is prepared from ground phosphogypsum and sulphuric acid solution with pH=0.5-2.5 until achieving liquid:solid ratio of 4-7. Sorption is carried out directly from the phosphogypsum pulp on a sorbent with sulphuric acid functional groups for 5-7 hours with solid:sorbent ratio of 4-7.
EFFECT: high efficiency of the method owing to higher extraction of rare-earth elements without a filtration step.
6 tbl, 6 ex
SUBSTANCE: method involves selective extraction of salts in volumes of nanopores of nanoporous conducting materials due to effect of electrostatic interaction of dipole moments of solvated ionic complexes of transition, rare-earth and actinoid elements with electric field of double electric layer of "nanopore wall - solution" boundary line. The method is implemented by subsequent filling of nanopore of nanoporous conducting material with the solution containing ionic complexes of transition, and/or rare-earth and/or actinoid elements, displacement from nanopore of ionic complexes of transition, rare-earth and actinoid elements weakly localised in nanopores by means of pressure of gases or liquids, by filling of nanopore with solution of inorganic acid of high concentration, and by extracting from nanopores of residual ionic complexes of transition, rare-earth and actinoid elements by means of pressure of gases or liquids. The above method can be implemented in an electrochemical cell.
EFFECT: obtaining cheap and competitive compounds of the above elements of high technical purity.
45 cl, 18 dwg, 4 ex
SUBSTANCE: invention can be used in the technology of obtaining the compounds of rare-earth metals at complex processing of apatites, and namely for obtaining of concentrate of rare-earth metals (REM) from phosphogypsum. Method involves sorption of rare-earth metals. At that, prior to sorption, phosphogypsum is crushed in water so that pulp is obtained in the ratio Solid : Liquid=1:(5-10). Sorption is performed by introducing to the obtained pulp of sorbent containing sulphate and phosphate functional groups, at the ratio of Solid : Sorbent=1:(5-10) and mixing during 3-6 h.
EFFECT: increasing REM extraction degree to finished product.
5 tbl, 5 ex
SUBSTANCE: method involves oxidation of micro production wastes at temperature of 550-650°C in air atmosphere for destruction of crystal latitude Nd2Fe14B so that Fe2O3, Nd2O3, Fe2B is formed and moisture and oil is removed. Then, anhydrous fluorides of rare-earth metals are obtained and their metallothermic reduction is performed for production of constant magnets. After oxidation from oxidated microwastes is completed, rare-earth metals are leached with nitric acid with concentration of 1-2 mol/l at temperature of 20-80°C. Obtained nitrate solutions containing rare-earth metals and impurity elements are processed with solution of formic acid with extraction of formiates of rare-earth metals in the form of the deposit cleaned from impurity elements, which includes iron, aluminium, nickel, cobalt, copper and other transition metals.
EFFECT: regeneration of rare-earth metals from production wastes of magnets and obtaining raw material containing rare-earth metals for reutilisation in production of rare-earth constant magnets.
2 cl, 2 tbl, 7 ex
SUBSTANCE: invention relates to methods of extracting a concentrate of rare-earth elements from wet-process phosphoric acid, which is obtained in a dihydrate process of processing an apatite concentrate, and can be used in chemical and related industries. The method involves sorption of rare-earth elements and thorium contained in wet-process phosphoric acid at temperature 20-85°C, wherein the sorbent used is a sulphoxide cationite, washing the saturated sorbent with water, desorption of rare-earth elements and thorium with concentrated ammonium sulphate solution to form a desorbate, and treating the desorbate with an ammonia-containing precipitant in form of ammonium carbonate or ammonia gas, which is fed in two steps, wherein at the first step the precipitant is fed until achieving pH 4.5-5.0 with precipitation and separation of a thorium-containing precipitate, and at the second step - until achieving pH of not less than 7 with precipitation and separation of a concentrate of rare-earth elements.
EFFECT: invention increases extraction of rare-earth elements while obtaining a non-radioactive concentrate of rare-earth elements.
4 cl, 4 ex
SUBSTANCE: method to extract holmium (III) cations from nitrate solutions includes ion floatation using an anion-type surfactant as a collector. Besides, the collector is dodecyl sodium sulfate in a concentration corresponding to stoichiometry of the following reaction: Ho+3+3C12H25OSO3Na=Ho[C12H25OSO3]3+3Na+, where Ho+3 - holmium cation, C12H25OSO3Na - sodium dodecyl sulfate. Moreover, ion floatation is carried out at pH=6.6-7.4, which makes it possible to achieve 90% extraction of holmium from aqueous solutions of its salts.
EFFECT: higher extent of holmium extraction.
1 dwg, 1 tbl, 1 ex
SUBSTANCE: invention relates to the method for production of pure lanthanum or its oxides from lean or industrial raw materials by method of ion floatation. The method to extract lanthanum La+3 cations from aqueous solutions of salts includes ion floatation using an anion-type surfactant as a collector. Besides, the collector is dodecyl sodium sulfate in a concentration corresponding to the stoichiometric reaction: La+3+3NaDS=La[DS]3+3Na+, where La+3 - lanthanum cation, NaDS - dodecyl sodium sulfate. Moreover, ion floatation is carried out at pH=7.8-8.1, which makes it possible to achieve 98% extraction of lanthanum from aqueous solutions of its salts.
EFFECT: higher extent of lanthanum extraction.
2 dwg, 1 ex
SUBSTANCE: invention relates to field of chemistry. By-product of production of chlorine-containing salts in form of unreacted sediment during dissolution of oxygen-containing aluminium compound with composition Al2O3nH2O, where n=0.5-2.9 in hydrochloric acid at higher temperature, is washed and dried. After that it is subjected to plasticisation with addition of nitric acid and water to acidic module 0.025-0.05, formation, drying and thermal processing. Thermal processing is carried out at temperature 400-1300°C.
EFFECT: invention makes it possible to obtain active aluminium oxide with improved properties, improve ecology due to application of wastes of production of aluminium chlorine-containing salts.
3 cl, 1 tbl
SUBSTANCE: invention relates to chemistry. Aluminium hydroxide sol is treated in a coaxial electrolysis cell with anode current density of 300-500 A/m2. The surface area of the anode of the electrolysis cell is greater than the surface area of the cathode by not less than two orders. The anode used is VT1-0 titanium with a ruthenium-titanium oxide coating and the cathode is X18H10T steel. The obtained precipitate is held in the mother solution. Aluminium oxide is obtained from the obtained finely dispersed aluminium hydroxide by thermal treatment at 500-550°C.
EFFECT: invention simplifies the process, enables to obtain finely dispersed aluminium hydroxide with a monophase bayerite structure and aluminium oxide from said aluminium hydroxide with particle size not greater than 500 nm.
2 cl, 1 dwg, 2 tbl, 3 ex
SUBSTANCE: ceramic powdered material contains aluminium oxide particles. Said particles have specific surface area (SSA) not less than 15 m2/g and not greater than 75 m2/g and sphericity quantified by at least one of (i) a mean roundness not less than 0.710 as measured by roundness correlation image analysis, and (ii) a concavity less than 20%. Concavity is the percentage of aluminium oxide particles based on a sample of at least 100 particles, which have a concave outer peripheral portion that extends along a distance not less than 10% of d50 by TEM inspection, the concave outer peripheral portion having a negative radius of curvature as viewed from the interior of the particle. The aluminium oxide particles are obtained by heat treatment, involving hot isostatic pressing (HIPing) of loose powder at pressure approximately not less than 0.1 ksi at temperature not lower than 300°C.
EFFECT: production of ceramic powdered material containing aluminium oxide particles for use as abrasive and filler with the required density with limited thermal balance, maximum sintering temperature and curing time.
16 cl, 25 dwg, 3 tbl, 5 ex
SUBSTANCE: invention relates to nanotechnology. Nanofibre is a tube made of corundum with nanothickness of walls or any fiber, covered with such tube. Corundum nanofibre is obtained by metallisation of any fiber with nanolayer of aluminium followed by oxidation of aluminium to the corundum and with the subsequent removal of the substance of the original fiber or without removing it.
EFFECT: obtained corundum nanofiber has superior strength and excellent thermal insulation properties.
SUBSTANCE: control method of ore-heating furnace operating mode for producing zirconia alumina involves measurement of voltage and current during melting, control of feeding the charge and degree of the electric arc development. Also, the value of the constant component of the phase voltage of each electrode is measured, then it is compared to a predetermined optimum value and in case of deviation from a set point the electric mode or dosage of the charge is adjusted to eliminate the deviation of the values of the constant component of phase voltage.
EFFECT: stabilisation of the melting process.
SUBSTANCE: invention relates to chemistry. The spherically shaped adsorbent-desiccant is prepared by balling moist powder of a nanostructured oxygen-containing aluminium compound. The granules undergo thermal-steam treatment in air at the first step at temperature 20-25°C for 1-20 hours, at the second step at 100-120°C for 1-20 hours and calcination at 450-550°C in a current of dry air and rate of heating to calcination temperature of 20-50°C/h for 2-6 hours. The nanostructured oxygen-containing aluminium compound of formula: Al2O3-x(OH)x·nH2O, where x is in the range of 0-0.28 and n is in the range of 0.1-0.4, is mixed with a modifying additive such as: CaO and/or Na2O, and/or MgO, and/or zeolite. A spherically shaped adsorbent-desiccant is obtained, which contains aluminium oxide in form of a mixture χ-, η-, γ- and is X-ray amorphous, and a modifying additive such as: zeolite and/or (in terms of) CaO and/or Na2O, and/or MgO is also obtained.
EFFECT: invention increases adsorbent capacity.
11 cl, 1 tbl, 35 ex
SUBSTANCE: invention relates to chemical industry, particularly to production of aluminium oxide hydrosol, which is used as a catalyst support, coagulant during water treatment and binder when producing shell moulds for precision casting from heat-resistant steel. Freshly deposited aluminium hydroxide is dissolved in aluminium hydrochloride at 20°C for 20-30 minutes and aluminium oxide hydrosol is obtained.
EFFECT: invention enables to improve quality of the product and safety of the process.
FIELD: process engineering.
SUBSTANCE: invention relates to dispersions of aluminium nano oxide intended for formation of coats. Proposed method of producing stable dispersion of aluminium nano oxide made from sol comprises dispersing aluminium nano oxide in dispersant solution containing ethylene glycol and/or 1,2-propandiol and phenolic or amide solvent. Invention covers also the method of applying coat on wire comprising preparation of aforesaid stable dispersion of aluminium nano oxide as described above.
EFFECT: higher stability aluminium nano oxide dispersion.
18 cl, 1 tbl, 15 ex
SUBSTANCE: invention relates to chemistry and can be used to produce powdered aluminium hydroxide and aluminium oxide. According to the first version, hydrargillite undergoes thermochemical and/or mechanochemical activation. The activation product is washed on a press filter at pH less than 9 and water is then added to the washed activation product in ratio solid:liquid equal to 1:(8-10). The obtained suspension is spray dried at 170-200°C. In the second version, the activation product is plasticised at pH 2-3 and temperature 140-160°C and water is then added to the plastification product until achieving solid:liquid ratio in the suspension of 1:(7.5-15), and the suspension is taken for spray drying at temperature 180-210°C. Aluminium hydroxide powder obtained using said method is annealed at temperature 450-650°C.
EFFECT: invention enables to obtain products of different phase composition.
5 tbl, 1 dwg, 16 ex
SUBSTANCE: invention relates to inorganic chemistry, particularly to a method of producing aluminium oxide nanocrystals. An aluminium compound is mixed with cellulose in water until formation of a homogeneous disperse phase. The disperse phase is filtered and heated to 500-850°C. The obtained aggregated aluminium oxide is put into an autoclave where it undergoes hydrothermal processing in an acidic medium containing an aqueous solution of an acid with concentration of 0.08-2.20 wt %, at temperature 180-220°C for 4-26 hours. The obtained nanosized boehmite is dried and annealed at 800-850°C for 2-3 hours. The aluminium compound is selected from aluminium chloride, nitrate, sulphate or hydroxide. The aluminium compound is mixed with cellulose in weight ratio of 1:1.3-2.0, respectively.
EFFECT: invention enables to obtain a homogeneous phase of non-aggregated non-crystalline aluminium oxide with grain composition in which the predominant particle size is less than 100 nm.
3 cl, 1 tbl, 3 dwg, 5 ex
FIELD: process engineering.
SUBSTANCE: invention relates to dressing of minerals, particularly to wet magnetic separation. Proposed method comprises feeding pump, affecting it by nonhomogeneous magnetic field and discharging separation products. Pump is affected by preset-intensity magnetic field to make magnetic particles afloat on pulp surface and stay thereon and to be mechanically removed therefrom and flushed by running water. Proposed device comprises working tool composed of flute 1, magnetic system 2, feeder 4 and separation product receivers 5, 6. Besides, device is equipped with, at least, one dressed product remover 7 and separation plates 8 for uniform pulp flow distribution arranged in flute. Note here that said flute makes a discharge channel 9,10 while aforesaid feeder is provided with pulp feed system 13.
EFFECT: higher efficiency and selectivity, simplified design and higher reliability.
4 cl, 3 dwg