SU884828A1 - Electric-corundum powder regeneration method - Google Patents

Description

(54) METHOD FOR REGULATING ELECTRIC ROUND POWDER

The invention relates to the drinking industry, in particular to methods for the regeneration of the erectrocorundum used in the casting of melted models from used forms and rods. There is a method of regenerating powders of refractory oxides of all fractions from waste forms used in the production of casting according to melted models, including chemical o6pa6oTJQr waste of alkali metal hydroxide followed by washing, drying and sieving LlJ However, this method is impossible to regenerate micropowders of electroorrhoids for regeneration of electrocorundum, but it was impossible The alkali introduced during regeneration and the products formed during the regeneration process are difficult to clean up from microcorones. The closest to the proposed technical essence and the achieved result is a method of regenerating electrocorundum powders from waste forms and from the stems produced during casting using models, which consists in crushing the waste forms and rods to obtain a product smaller than 25 mm, vibrotizing of silica film, separation microporous fraction from grinding grain, rubbing of fraction (-0.063), subsequent classification of micropowder into fraction (-0.063 mm) - (- “- O, O20 mm) and (-O, 020mm) (10.07 mm), screening the fraction (-0 , 8 mm) (+ O, O63 mm) 2. However, it is fireproof with The sediment prepared on the basis of electrocorundum regenerated by this method has a low sedimeitioin (L resistance due to the increased content of silica, resulting in micro-powders of trocorundum ale quickly settling, stratification of the suspension occurs, and ceramics layers on the model are uneven in thickness. The purpose of the invention is to increase the sediments. Tatio stability of ceramic suspension Hk based on micropowders 4 hours a1 of 8 electui corundum and increase the strength of ceramic molds and rods. In order to achieve the set chain in the method of regeneration of the powder of epec-corundum and from spent ceramic molds and rods when drinking according to the produced models, using the crushed waste molds and rods, scrubbing the cream film is not herem, separating the micropowder fraction from the cream, fraction of the fraction (-0.0636), separating the micropowder fraction from the liquid, 0.3063; micropill and drying, after rubbing fractions {and (0-0.063 mm), carried out the first classification, the fraction (-O, OO7 mm), crushed the remaining micropowder to (-0.007 mm) - (+ 0 mm), and the content of the fraction (-O, O07 mm) brought to 15-2O% of the total weight of micropowder followed by treating it with a strong inorganic acid, drying and performing a second klassifikashga raadepeniem micropowder on fraksh1I (-O, O63 mm) - (, O20mm) and (-0,020mm) (Yu mm). The method is carried out as follows. Spent casting molds with a size of up to 2OO mm are fed to crushing to the size of pieces (-25 mm), which is carried out in a jaw crusher. RZchZdrob foam material enters vibrating rubbing, where the films to | Instead, the material goes to the Pepper Classification Material ("-0.063 mm) enters the micropowder compartment, and the material (+0.063 mm) is transmitted and the screen is over the upper limit (О, 80mm Material (-" - OiSO mm) enters for crushing into a vassov crusher and a scrubbing apparatus is returned, the material (0.8O mm) is transferred to the second classification to separate the micropowders of the fraction (-0, O63 mm) which is transported to the mic feed unit: with ps | 5s1kov, while Material. MKi Survey) - (- 0.80 mm) enters the crushing unit to a self-contained vibration meter. After the second vibration erase, the material passes the third classification with a micropowder scrap (-0.063 mm), which is also transported to the micropowder area, and the material (+0.063 mm) undergoes filtering, drying and magnetic separation, and then dissipates into the following fractions: (-0.80 mm) (Yu, 40); - (- 0.40 mm) -. (+ 0.40 mm) -O + + O, 25 mm); (-0.25 mm) - (+ 0.16 mm); (-0.16 mm). At this time, the regeneration of the electrocorundum grinding core is completed. Further, the material (-0.063 mm), which entered the microelectrum section, goes through the thickening, filtering operations and goes to the third vibrator to remove the silica film. After that, the unit enters the pulping operation, where the exact ratio is established. 1O, where T is solid; F - liquid. The pulp of this composition is supplied to the first classification by (± 0.063 mm). Then, the material enters the second classification, where the fraction (O, OO7 mm) is separated, and removed to the dump. And the fraction (-O, O63 mm) - (+ 0, O07 mm) enters the vibrating-rubbing apparatus for crushing to a fraction (-0.063 mm) - (+ 0mm), and the content of the fraction (-0.007 mm) is adjusted to 15-20 % of the total microplastic. The lower limit of the fraction is selected from the conditions of sedimentation stability of the suspension, and the upper one from the conditions ensuring the strength of ceramics. After crushing, the material is treated with a solution of a strong inorganic acid, for example, 3–6% hydrochloric acid, and is fed to the third classification, where the micropowder is divided into fractions (-0.063 mm) - (+ O, 02O mm) and (2-O , О2Омм). The minimum percentage of acid concentration is selected from the condition of obtaining the greatest effect of treatment, the maximum percentage - from the condition of the minimum harmfulness of the work. Then the final operations of drying and magnetic separation are carried out. After scrubbing the fraction (-O, O63 mm), a pepper classification was carried out to remove the fraction (-0.007 mm), the microplate was crushed to (-0.063 mm) - (+ ohm):. moreover, the fraction (-0.007 mm) is adjusted to 15-2O% of the total weight of the micropowder, treated with a solution of a strong inorganic acid, such as hydrochloric, and the classification is carried out, sectioning the micropowder into fractions (-0.063 mm) (+ 0, О20 mm) and (-0, O2O mm) - (- “- 0 mm). . These fractions in a certain ratio are used to prepare a ceramic slurry and. Example. The proposed method for regeneration of electrocorundum is reproduced under laboratory conditions, 15 kg of waste casting molds are crushed with a laboratory roller crusher to lump sizes less than 15 mm and loaded into a laboratory vibrating mill for rubbing. Otter It is produced within 5 hours. After scrubbing, the micropowder fraction (-0.063 mm) is separated on laboratory classifiers of the Buiko Cone type. Then, the fraction (-O, OO7 mm) is separated from the micropowder fraction on laboratory sedimenters of the AG-1 type. Next, the remaining material of the fraction (Ю.U. Ob3 mm) - (1О, ОО7 mm) is loaded into the laboratory vibrator mill along with cheers crushing. The content of the fraction (-O, OO7 mm) is adjusted to 152 O% of the total weight of the micropowder. The two microcorundum micropowder samples obtained after crushing are divided into 4 parts each and treated with a solution of a strong inorganic acid. Four treatment options were tested in acid: in 3% hydrochloric acid; in 6% hydrochloric acid; in 3% -41% sulfuric acid; in 6% sulfuric acid. Further, all the samples of regenerated electrocorundum are divided into laboratory classifiers such as the Buiko Cone into fractions {-0.063 mm) - {+ O, 02O mm) and (-O, O2O mm) - (+ 0 mm). Then the electr samples After crushing and 1.999 1.983 acid treatments Without the use of crushing and acid treatments (by a known method) 1.999 1.963

From the data in the table it can be seen that the sedimentation rate of particles in suspension by the proposed method is 3 times less, and therefore sedimentary stability is 3 times faster than the suspension according to a known method.

The suspension prepared using electrocorundum, regenerated by the proposed method, includes a regenerated microcorundum of electrocorundum fraction (-O, O63 mm) - (+ 0 mm) including the content of the fraction (-0.007 mm), 15-20%; obtained after crushing in a mill and treated with a 3% solution of hydrochloric acid 1OO wt.%; hydrolyzed ethyl silicate 4O in excess of 1OO% (solid to liquid ratio 3: 1).

The composition of the suspension, prepared using electrocorunite recovered in a known manner, includes the regenerated micropowder fraction

(-0.063 mm) - (+ O mm) 1OO wt.%; hydrolyzed ethyl silicate-40 over 100 wt.% (solid-to-liquid ratio 3.1), Ceramic bending strength, kgf / cm, / Made on the basis of regenerated aluminum oxide with crushing and subsequent processing in acid solution (proposed method):

At 2 ° С 65.8; 66.6; 63.8 At 950C 99.9; 84.7; 10.4,

The strength of ceramics in bending, kgf / cm, made on the basis of regenerated electrofusion (in a known manner) g At 20 ° C 49.0; 46.9; 49.0 With 43.4; 42.1; 44.5 Thus, the proposed method of regenerating electrocorundum powder provides an increase of 2-3 times in the sedimentation stability of the refractory suspension, made on the basis of the regenerated electrocorundum, and the improvement of the carbon corundum takes place on laboratory equipment. The method for determining the sedimentation stability of a refractory suspension is based on a change in the density of the suspension over time. A sample of the refractory slurry is prepared on the basis of regenerated electrocorundum with a viscosity of 30–40 s (according to Bi-4). After a determined period of time, the density of the suspension is measured by the weighing method. After each. Once the density was measured, the suspension was again stirred for 15 minutes on a laboratory mixer, and the density was measured again after a certain time after the suspension was allowed to stand. The suspension is allowed to stand for 1 3; five; 7; 10 and 15 min. The suspension is weighed in a volumetric flask (1OO cm) on an analytical balance. The results of skcnepsiMeHTa are shown in the table. 1.955 1.933 1.98O 1.962 1.901 1.862 1.780 1.938 78 The total ceramic surface of the surface increases by 2 times. The strength of ceramics increases by 40%. Formula and method of regenerating pschmika eectro corundum and used ceramic molds and rods with this material. models, including crushing of waste forms and cores (picking up silica films, separating the micropowder fraction from grinding, scaling off the fraction (-O.BT mm), classification of the micropowder and drying, which was done so that the sedimentation of The stability of ceramic suspensions based on microporous electrocorid and increase in strength of ceramic molds and rods, scrubbing the fraction (-O, O63 mm), carried out the first classification, removing fraction 8 (-0, ОО7 mm) crushed the remaining micropowder to (-0.007 mm) - (+ 0 mm), and the fraction content (-O, OO7 mm) is brought to W the total weight of the micropowder followed by treatment with its strong inorganic acid, drying and conducting the second classification with separation of the micropowder into fractions {-0.063 mm) - (+0,020 mm) and (-0,020mm). (+0 mm). Sources of information taken into account in the ex ergy 1. Authors certificate of the USSR No. 389877, cl. B 22 C 5 / 00,1971. 2. Research and development of the technological process of regeneration of grinding sands and micropowders from spent casting molds for the composition of electrocorundum-electrolyte and the development of design documentation for the installation for regenerating electrocorundum. Technical Report on the topic number 6-1205-3210-291-12-110. M, NIAT. 1978. with. 110.

Claims (1)

Claim The method of regeneration of electrocorundum powder from spent ceramic molds and cores during investment casting * * · casting, including crushing the worked molds and cores, rubbing silica films, separating the microfine fraction from the grinder, rubbing the fraction (-0.063 mm), micropowder classification and drying, characterized by the fact that, in order to increase the sedimentation stability of a ceramic suspension based on a micropowder fraction of electrocorundum and increase the strength of ceramic molds and cores, after rubbing the fraction (-0.063 mm) carry out the first classification, removing the fraction, the powder, followed by its treatment with strong inorganic acid, drying and conducting the second classification with the separation of micropowder into fractions (-0.063 mm) - (+ 0.020 mm) and (-0.020 mm) · (+0 mm )