Electric Impact Wrench,Impact Wrench Battery,Cordless Impact Wrench,Drive Impact Wrench jinyunzhaoshigongjuyouxiangongsi , https://www.zscartools.com
Iron tailings brick
1. Iron tailings made of non-burning bricks
Shan Institute of Mining Qidashan use, iron ore tailings Waitoushan successfully made the unburned brick, wall tiles which are unburned fine tailings (SiO 2> 70%) as the main raw material, with A small amount of aggregate, calcium cementitious material and admixture are added, and an appropriate amount of water is added, uniformly stirred, and then molded under a pressure of 19.6 to 114.7 MPa on a 60-ton press, and subjected to standard curing (natural curing) for 28 days after demolding. , into the finished product, the process flow is shown in Figure 1. The two tailings bricks of Qi Dashan and Shantou Mountain have been tested, and all the indicators have met the requirements of No. 100 standard bricks stipulated in the Technical Conditions for Non-sintered Clay Bricks promulgated by the State Bureau of Building Materials.
Figure 1 Production process of tailings-free brick
Dalian University of Technology collaborates with Dagangshan Iron Mine of Anshan Iron and Steel Co., Ltd., using iron tailings and lime as the main raw materials, adding appropriate amount of modified materials and admixtures, and developing the steamed tailings bricks with better physical properties. Can meet the requirements of standard bricks above 100.
Meishan Meishan iron ore processing plant using a number of sand tailings added (Ore: sand = 3: 1) was added 3% of cement, from 8% to 10% water and 2% to 3% of additives F-1, made A standard brick sample of 240 mm × 115 mm × 53 mm is then subjected to various tests such as flexural strength, compressive strength and fire resistance. The main technical indicators have reached the requirements of "Technical Conditions for Non-sintered Clay Bricks", and the number can reach above 75.
Second, iron tailings production wall, floor decorative brick
Maanshan Mine Research Institute uses fine-grain tailings from Qidashan and Shantoushan iron ore, adding a small amount of inorganic cementitious materials, ordinary Portland cement, white Portland cement and appropriate amount of water. After even mixing and stirring, The second layer (base layer, surface layer) is used to process the decorative tiles. The production process is shown in Figure 2. The product has been tested and proved to have an average compressive strength of 19.6 MPa and a flexural strength of 5.0 MPa. The alkali resistance and corrosion resistance are strong. Iron tailings make decorative tiles, the process is simple, the raw material cost is low, the physical properties are good, the surface is smooth and beautiful, and the decorative effect is equivalent to other decorative tiles (such as cement floor tiles, ceramic glazed tiles).
Figure 2 production process of decorative tiles
Tongji University cooperates with Magang Gushan Iron Mine to use tailings powder with a particle size of 0.15mm or less as the main raw material, and mixes 10% to 15% of quicklime powder to be pressed into a wall of various specifications and shapes to build a clear water wall. If Portland cement is used as the cement, the effect is better and the process can be further simplified. The decorative tiles produced are more suitable for exterior wall veneers. They can also be treated with unsaturated polyester resin in the performance of the finished bricks, and the pigments of different colors can be transferred to make the color smooth tiles of monochrome or imitation natural marble pattern. It can also be used as a dark brown smooth brick without resin or other paints. It can replace ordinary tiles and artificial marbles for interior decoration. The tailings brick treated by atmospheric pressure steam curing has a compressive strength of 12.4 MPa and a flexural strength of 3.0 MPa. After adding an appropriate amount of mix and a small amount of gypsum powder coal ash, the strength can be increased to more than 20.0MPa. Moreover, this tailings brick has been tested as a material that is resistant to the atmosphere.
Third, iron tailings production machine pressed lime sand brick
Ridge Iron Concentrator characteristics of gold mine, using a pressing machine tailings sand-lime brick, the brick is mainly iron tailing, adding an appropriate amount of cement was prepared by dry mixing evenly, then add a small amount of binder material is compacted, Improve its surface activity, after being pressed and formed by a brick press, it is naturally cured. The process is simple, no need to burn, no steaming, not only save energy (about 0.16t per 10,000 bricks than clay bricks), and no pollution, the produced lime sand bricks are accurate in size, sharp edges and corners, and neat appearance. The brick body is straight, which can save the amount of plastering, improve the efficiency and reduce the cost. The mine was completed in October 1989. The production of lime sand bricks has been tested, and the physical performance indicators have reached the technical requirements of No. 100 standard for mechanically pressed lime sand bricks.
Fourth, iron tailings to make carbonized tailings bricks
The Yuquanling Iron Mine has developed and utilized tailings as a carbonized tailings brick since 1986, and has achieved results. The carbonized tailings brick is a masonry material which is made of tailings sand and lime as raw materials, prepared by billet, pressed and formed, and carbonized by carbon dioxide (CO 2 ) of lime kiln exhaust gas.
(a) principle
The semi-finished product of the carbonized lime sand brick is firstly formed by the hydration and hardening of the quicklime, firstly, the calcium hydroxide crystal is formed, and then carbonized by the lime kiln exhaust gas carbon dioxide (CO 2 ), and finally the calcium carbonate crystal (CaCO 3 ) is formed, and the water is combined with the water. The product is evaporated and the product is finally carbonized. The chemical reaction process is as follows:
CaO+H 2 O→Ca(OH) 2
Ca (OH) 2 + nH 2 O + CO 2 → CaCO 3 + (n + 1) H 2 O
(2) Process
80% to 85% of tailings sand and 15% to 20% of quicklime powder are proportioned, and about 9% of water is added to stir and dissolve. Then, it is formed by an eight-hole brick press, dried before drying in the kiln or naturally dried. Less than 4%, then enter the tunnel kiln for carbonization, carbonized carbon dioxide content of 20% to 40%, carbonization depth of more than 60%, after the kiln can get the finished product.
The brick production process is simple, the machine and the soil sample are all available, and there are no technical problems that are difficult to grasp. Any tailings sand and limestone can be mass produced.
Five, serpentine glazed tiles, tiles
The tailings discharged from iron and iron in Weihai City are mainly serpentine slag, with an annual discharge of 100,000 to 150,000 tons. In order to solve the comprehensive utilization of serpentine slag, serpentine slag glaze was carried out from May to July 1987. The feasibility test of the brick making process. The main mineral components of serpentine ancient slag are silicate minerals such as serpentine, olivine, diopside , tremolite and hornblende. The grinding grain size is fine and uniform, generally -0.256mm, and the content is 85%. For the physicochemical properties such as mineral composition, chemical composition and particle size of the slag, it can be directly used for making ordinary civil architectural ornaments such as bricks and tiles. The main raw material of the surface material.
(1) Principles of serpentine slag glazed tiles and tiles
The principle of serpentine slag glazed tiles and tiles is mainly based on the melting-crystallization characteristics of its minerals. During the high-temperature melting process of minerals from solid phase to solid phase, the repulsion between the molecules in the material increases, and the binding force of the intermolecular bonds decreases; while in the crystallization process from the solid-liquid phase to the solid phase, the molecules in the material The attraction between the two increases, and the binding force of the intermolecular bonds increases. Rich in SiO 2, Al 2 O 3, CaO, MgO, Fe 3 O 4 glazed tile parison serpentine slag chemical characteristics of the high temperature melt crystallization, complete solid phase → the solid-liquid phase solid phase → The physicochemical reaction process enhances the bonding force between the materials and the molecules, resulting in changes in the hardness, strength, corrosion resistance, water immersion and the like of the fired tiles, and improves various physical properties.
(2) Production process
The main production processes of serpentine slag glazed tiles and tiles are: raw material preparation, blank forming, glaze processing, hot air drying, and melt crystallization.
Raw material equipment: Mainly based on the chemical composition and physical characteristics of the slag, the billet raw material is prepared higher than the refractoriness and fineness of the ordinary brick. Preform material generally should meet the following requirements: chemical composition SiO 2 60% ~ 70%, Al 2 O 3 10% ~ 25%, CaO + MgO0 ~ 25%, Fe 3 O 4 3% ~ 15%, a particle size larger than 0.25mm in 22%, 0.25 ~ 0.05mm accounted for 40%, 0.05 ~ 0.005mm accounted for 45%, less than 0.005mm accounted for 12%. The plasticity index is less than 7 (according to the liquid limit plastic limit), the drying line shrinks less than 12%, and the firing line shrinks less than 8%.
Blank forming: The prepared raw materials are blended into a plastic form by a stirrer, and cut into a blank, and the blank is sent into a mold and pressed into a blank to be dried in a drying chamber.
Glazed processing: After the surface of the near dry blank is treated by surface finish, the glaze is sprayed, that is, the base glaze and the colored glaze are sprayed as needed. After drying in a drying chamber, the moisture content is less than 1% after the kiln.
Melt crystallization: The dried blank is put into the kiln, and the porous kiln and tunnel kiln are generally used for refractory materials. 0~14h can be heated at an average temperature of 50 °C per hour, the average temperature can be increased by 30 °C every 14th to 20h, the temperature can be poured to 25~28h, the temperature in the kiln is 1000~1050°C, and the material is solid-melted. 6h, cooling and crystallization.
The glazed tile has simple manufacturing process, wide raw materials, low cost and broad utilization prospects.
Six or three free tailings bricks
Angang has made iron-free tailings powder as the main raw material to produce three-free tailings bricks with no pressure, no steaming and no burning. This brick has been tested to meet the requirements of JC153-75MU10 standard and has passed provincial technical appraisal.
(1) Main raw materials and quality requirements
The main raw material of the brick is iron tailings powder as the main material, lime is the curing agent, and cement is the binder.
Iron tailings powder: The iron tailings produced by the Sanzhuo Concentrator in Anshan District, its chemical composition, physical properties and particle gradation are shown in Table 1, Table 2. The density is 2.85 g/cm 3 , the bulk density is 1480 kg/m 3 , the mud content is not more than 3%, and the water content is not more than 2%.
Table 1 Chemical composition of iron tailings powder
chemical composition
SiO 2
FeO
MgO
Al 2 O 3
CaO
FeCO 3
S
P
Burning vector
other
Quality score /%
70.53
4.07
2.74
1.06
2.44
8.17
0.1
0.033
3.68
3.11
Table 2 Iron tailings powder particle grading
Screen size / mm
0.6
0.4
0.3
0.15
0.1
0.08
+0.076
-0.076
Separate screening /%
0.26
1.6
9.0
33.8
26.5
0.43
10.01
18.41
Lime: The quicklime powder is a curing agent, and its effective CaO content is not less than 65%, the loose bulk density is 1100 kg/m 3 , and its particle gradation is shown in Table 3. A suitable amount is 10% to 20%.
Table 3 Particle grading of quicklime powder
Screen size / mm
0.6
0.3
0.08
+0.076
-0.076
Separate screening /%
14.6
27
25.6
0.25
32.51
Blended fly ash: Fly ash is from a wide range of industrial waste slag, its density is 2.2g / cm 3 , the bulk density is 1000kg / m 3 , the fineness of 0.08mm square hole sieve has a sieve residue of not more than 8%, burning The loss is not more than 7%, and the sulfur trioxide content is not more than 3%. The chemical composition is shown in Table 4. A suitable dosage is about 15%.
Table 4 Chemical composition of fly ash
chemical composition
SiO 2
Al 2 O 3
Fe 2 O 3
CaO
MgO
S
Quality score /%
48.74
35.76
5.30
3.06
1.19
0.26
The activator and the composite admixture: the activator is hemihydrate gypsum (CaSO 4 · 1/2H 2 O), and the compound admixture is a self-dispensing K agent. The amount thereof is preferably from 0.5% to 1.0%.
Cement; Portland cement No. 325 or No. 425, ordinary Portland cement or slag Portland cement. The dosage is controlled by the cost, and the general cement content is not more than 15%.
(two) mechanism
Free tailings brick powder to achieve pressure, steam-free, non-burned, to be formed at room temperature with its raw material silicate, aluminate and hydration sulphoaluminate hydrates premise. The light diffraction analysis showed that the bricks contained more C-S-H tobo mullite gel or crystals, and a small amount of hydrated calcium sulphoaluminate needle crystals existed. Because the composite admixture added to the brick is a highly effective surfactant, the dispersion and adsorption effects increase the cement hydration point, improve the interface state of cement, lime, tailings powder and fly ash particles, and hydration reaction. It is accelerated and hardened at room temperature to produce considerable strength. The Ca(OH) 2 produced by cement hydration further reacts with the active Al 2 O 3 and SiO 2 in the tailings powder and fly ash to form a low-alkaline silicate and aluminate hydrate, which promotes the compactness and strength of the brick structure. improve.
(3) Process
Mainly including ingredients, mixing, aging, forming, curing
According to the ratio of tailings powder: cement: fly ash: lime = 6:1.5:1.5:1 or :7:1:1:1, add the activator (gypsum) and mix dry. Add water and K agent and mix well by hand. The water consumption is generally 20% to 30% of the weight of the tailings powder. After stirring, let stand for 20 to 30 minutes, put it into the mold after aging, smooth the surface, remove the mold after 24 hours, and maintain it in air or water for one month. Its intensity in water is about 20% to 30% higher than in air.
The use of the process of brick making can be applied in a large amount of industrial waste residue, which is conducive to opening up material resources and saving energy, and the cost is reduced by nearly 10% compared with the existing ash slag brick.
Seven, vitrified brick
Beijing University of Science and Technology conducted a pilot study on the use of Damiao vanadium- titanium magnetite tailings to make vitrified bricks. The use of the full tailings of the Damiao Iron Mine made a laboratory with various performance indicators meeting the requirements of commercial vitrification. Products.
(1) Raw materials
Temple ore tailings: main mineral plagioclase, pyroxenes, chlorite, epidote gangue minerals. The tailings were ground and chemically analyzed. The results are shown in Table 5.
Table 5 Chemical analysis results of tailings
chemical composition
Fe 2 O 3 +FeO
Al 2 O 3
MgO
K 2 O
Na 2 O
CaO
TiO 2
P 2 O 5
MnO
SiO 2
Quality score /%
16.48
16.26
3.62
1.02
3.02
6.79
4.28
0.62
0.15
43.02
Clay: montmorillonite as main mineral component, the chemical composition is as follows: SiO 2 68.04%, Al 2 O 3 16.46%, K 2 O0.22%, Na 2 O2.31%, CaO0.29%, MgO6.20%, Fe 2 O 3 , loss on ignition of 5.92. Its incorporation amount is 10%.
(2) Process
The tailings are mixed with the clay in a certain proportion, and the mixture is ground to -0.043mm and not less than 98%, and then the dried material is added to 5% water for granulation, and the pellet is made into a cylindrical warm billet under the pressure of 38 MPa. Then, it is calcined at 1145～1150°C, and the fired sample can be polished to obtain brown vitrified brick. After testing, its performance indexes are in line with the requirements of commercial vitrified brick.
If calcined in a reducing atmosphere, the brick and the charcoal powder are placed in the same crucible, sealed, and the brick and the carbon powder are not in direct contact, otherwise part of the magnetite directly contacting the carbon powder is reduced to ferrous oxide and Melt flow occurs with metallic iron. The result is a black body that has a bright black color after polishing.
The original tailings of the Dumiao Iron Mine can be made into brown vitrified bricks and black graded bricks of quality in line with commercial vitrified bricks. From the range of green strength and firing temperature range, it is possible to carry out expansion experiments and industrial experiments.