CN105798223A - Technology for casting molding sand through coal gangue - Google Patents
Technology for casting molding sand through coal gangue Download PDFInfo
- Publication number
- CN105798223A CN105798223A CN201610168398.9A CN201610168398A CN105798223A CN 105798223 A CN105798223 A CN 105798223A CN 201610168398 A CN201610168398 A CN 201610168398A CN 105798223 A CN105798223 A CN 105798223A
- Authority
- CN
- China
- Prior art keywords
- gangue
- coal gangue
- molding sand
- technology
- sand
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C5/00—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose
Abstract
The invention discloses a technology for casting molding sand through coal gangue. The technology comprises the following steps that firstly, the coal gangue is selected; the selected coal gangue is roasted to the temperature ranging from 1,400 DEG C to 1,500 DEG C, and insulating is conducted for a period of time; and the roasted coal gangue is crushed, and the molding sand is obtained. The technology has the beneficial effects that with the development of coal production, a large amount of coal gangue is piled up like a mountain, the non-combusted coal gangue can be spontaneously combusted in the atmosphere, and a large amount of sulfur containing harmful gas is generated and does harm to people, livestock and plants; and according to the technology for casting the molding sand through the coal gangue, the molding sand is produced through the abandoned coal gangue, the problems that the abandoned coal gangue occupies a large amount of land and pollutes the environment are solved, and the abandoned coal gangue is turned into wealth. In the technology, the molding sand is produced through the screened coal gangue, the content of silicon dioxide and aluminum oxide in the selected coal gangue and the mass ratio of the silicon dioxide to the aluminum oxide correspond to the mass ratio of silicone to aluminum in mullite, and the yield and the quality of the produced molding sand are improved.
Description
Technical field
The technique that the present invention relates to a kind of casting sand, is specifically related to a kind of work using gangue casting sand
Skill.
Background technology
Gangue is the solid waste of discharge during coal mining process and coal washing, be a kind of in coalification course with
The black gray expandable rock that a kind of phosphorus content of coal seam association is relatively low, harder than coal.Its main component is three oxidations two
Aluminum, silicon dioxide, additionally possibly together with quantity not wait iron sesquioxide, calcium oxide, magnesium oxide, sodium oxide,
Potassium oxide, phosphorus pentoxide and trace rare element.
China has accumulated gangue about 1000Mt over the years, and continue to every year discharge about 100Mt, not only heap
Long-pending take up an area, and can also spontaneous combustion contaminated air or cause fire, the material produced after burning have sulfur dioxide,
The harmful gass such as nitrogen oxides, oxycarbide and flue dust, the leaching water of outer gangue will pollute surrounding soil and
Subsoil water, this not only pollutes environment and affects the healthy of Residents in Mining Area.Therefore coal gangue pollution is solved
Environmental problem seems more and more prominent.
Molding sand is used for the material of moulding in casting, and the effect in Foundry Production is particularly important, and molding sand is to casting
The labor condition of part quality, productivity, cost and workman all has an impact.Cause because of the poor quality of molding sand
Casting wasted product accounts for the 30%-50% of the total waste product of foundry goods.Therefore improve molding sand quality, develop resource extensively, work
Skill new molding sand of good performance has great importance.And from the chemical composition analysis of gangue, through calcining
Gangue grog, be with aluminium oxide and aluminate-silicate refractory that silicon oxide is basic chemical composition, profit
It is cast as sand, aboundresources with gangue, there is obvious economic benefit and social benefit.
Summary of the invention
It is an object of the invention to provide a kind of technique using gangue casting sand.
It is an object of the invention to be achieved through the following technical solutions:
A kind of technique using gangue casting sand, comprises the following steps:
(1) gangue is chosen；Because mullite is the effective ingredient of molding sand, the number of mullite is molding sand grog
Good and bad most important mark, and the molecular formula of mullite is 3Al2O3·2SiO2, so gangue is forged
Choose before burning, to ensure the quality of fluid origin molding sand.Can also be surplus after using coal gangue power generation
Chosen material in remaining coal ash.
(2) by the calcined coal gangue chosen in step (1) to 1400-1500 DEG C, and it is incubated a period of time；
(3) gangue after calcining is pulverized, obtain molding sand.
Further, choosing the mass fraction containing silicon dioxide and aluminium sesquioxide in step (1) is
The gangue casting sand of 40%-90%.If silicon dioxide and the comparision contents of aluminium sesquioxide in gangue
Low, it is then not possible to formed mullite, so the gangue chosen need to ensure containing silicon dioxide and three oxidations
The content of two aluminum contains within the scope of silicon, aluminum amount at mullite.
Further, silicon dioxide is 0.25-0.85 with the weight ratio of aluminium sesquioxide.Dioxy in gangue
SiClx is also the key factor affecting mullite productivity with the weight ratio of aluminium sesquioxide.
Further, the particle diameter of the gangue chosen in step (1) is 4-6cm.So ensure gangue
Fully burning.
Further, described in step (2), the heating rate of calcining is 80-120 DEG C/h, because of before calcination
Solids bulk together, with the presence of a large amount of spaces, along with the raising of calcining heat, starts between granule to produce key
Closing and reset, fading away in big space, temperature raises again, and intergranular point cantact is expanded into face contact pore
More and more less, and may finally get rid of pore, i.e. gradually rising along with temperature, intensity and density the most gradually
Improving, this is favorably improved the quality of produced molding sand.
Further, step (2) enters after the calcining heat of gangue reaches 1400-1600 DEG C insulation
In the stage, the time of described insulation is 2-2.5h.The calcining heat of gangue is the key factor forming mullite,
When temperature is less than 1100 DEG C, calcines and do not generate mullite, when temperature is increased to
When 1200 DEG C, have a small amount of mullite and occur, but the primary product at a temperature of this is tridymite, works as temperature
Reach the formation speed of mullite when 1400 DEG C than very fast, the yield of mullite when temperature is increased to 1600 DEG C
Substantially without significant change.When calcining heat reaches 1400-1600 DEG C, then it is incubated 2-2.5h, does not comes
Stone produces and substantially tends towards stability.
Further, described in step (3), the gangue after calcining is first cooled to 20-30 DEG C, then carries out powder
Broken.
Further, described in step (3), the particle diameter of molding sand is 40-80 mesh.
The technique that the invention have the benefit that use gangue casting sand of the present invention, utilizes useless
The gangue abandoned produces molding sand, it is achieved that turn waste into wealth.Because of along with the development of coal production, a large amount of gangues
Pile up like a mountain, unburned coal gangue can spontaneous combustion in an atmosphere, produce substantial amounts of sulfur-bearing harmful gas, people and animals planted
All there is harm, and the technique of use gangue casting sand of the present invention, use discarded gangue
Produce molding sand, not only solve discarded gangue and take a large amount of soil, pollute the problem of environment, and make it
Turn waste into wealth.
In technique of the present invention, use and produce molding sand, selected gangue through grate coal spoil
Middle silicon dioxide is consistent with silicon, the mass ratio of aluminum in mullite with content and the mass ratio thereof of aluminium sesquioxide,
Improve yield and the quality producing molding sand.
The calcining heat of the technique of use gangue casting sand of the present invention takes the orientation progressively heated up
Calcine, be so favorably improved the quality of molding sand, because solids bulk together, has a large amount of before calcination
Space exists, and along with the raising of calcining heat, starts produce bonding and reset between granule, and big space gradually disappears
Losing, temperature raises again, and it is more and more less that the intergranular point cantact of intergranular point cantact is expanded into face contact pore,
And may finally get rid of pore, i.e. gradually rising along with temperature, intensity and density and also gradually step up, this has
Help improve the quality of the molding sand produced.
The technique of use gangue casting sand of the present invention is after reaching uniform temperature, through one section
Temperature retention time is pulverized again, makes the production of mullite tend towards stability because carrying out after reaching uniform temperature being incubated,
And the holding temperature of the production technology of the present invention is 1400-1600 DEG C, gangue is through more than 1400 calcinings
Lose water of crystallization, and other Organic substance the most all after-flames, therefore the gas-forming property of the moulding sand mixture produced is than quartz
Sand is low, and raising rate is also slow, and this performance substantially increases the quality of the foundry goods using molding sand to produce, such as:
The casting defects such as the sand holes of foundry goods, bubble can be reduced, help to maintain the clean and tidy smooth of cast(ing) surface.
Detailed description of the invention
Embodiment one
Choose the gangue that the mass fraction containing silicon dioxide and aluminium sesquioxide is 40%, and contained dioxy
The weight ratio of SiClx and aluminium sesquioxide is 0.25, because of mullite number be good and bad most important of molding sand grog
Mark, and the molecular formula of mullite is 3Al2O3·2SiO2, so selecting before gangue is calcined
Take, to ensure the quality of fluid origin molding sand.
Because the calcining heat of gangue is the key factor forming mullite, only when temperature is higher than 1100 DEG C
Just having mullite to generate, when temperature reaches 1400 DEG C, the formation speed of mullite compares very fast, when temperature liter
High to the yield of mullite when 1600 DEG C substantially without significant change.When calcining heat reaches 1400 DEG C, then protect
Temperature 2h, such mullite produces and substantially tends towards stability, because the motion that temperature raises particle can increase, activates
Can reduce, then the defect of crystals increases, and the particle participating in diffusion is also increased by, thus solid state reaction
Accelerating, product increases, and constant temperature time is the longest, and the thickness of conversion zone increases thus extends constant temperature time,
Product can be made to increase.For ensureing that gangue can fully burn when burning, the particle diameter of the gangue chosen
For 4cm, during calcining, ensure that calcining heat raises 80 DEG C per hour, because of solids bulk before calcination together,
With the presence of a large amount of spaces, along with the raising of calcining heat, start between granule produce bonding and reset, big space
Fading away, temperature raises again, and the intergranular point cantact of intergranular point cantact is expanded into face contact pore more
Come the least, and may finally get rid of pore, i.e. gradually rising along with temperature, intensity and density and the most gradually carry
Height, this is favorably improved the quality of produced molding sand.
It is ground into, when gangue after calcining is cooled to 20 DEG C, the granule that fineness is 40 mesh again.
Embodiment two
Choose the gangue of mass parts mark 60% containing silicon dioxide and aluminium sesquioxide, and contained dioxy
The weight ratio of SiClx and aluminium sesquioxide is 0.5, because of mullite number be good and bad most important of molding sand grog
Mark, and the molecular formula of mullite is 3Al2O3·2SiO2, so selecting before gangue is calcined
Take, to ensure the quality of fluid origin molding sand.
Because the calcining heat of gangue is the key factor forming mullite, only when temperature is higher than 1100 DEG C
Just having mullite to generate, when temperature reaches 1400 DEG C, the formation speed of mullite compares very fast, when temperature liter
High to the yield of mullite when 1600 DEG C substantially without significant change.When calcining heat reaches 1500 DEG C, then protect
Temperature 2.2h, such mullite produces and substantially tends towards stability, because the motion that temperature raises particle can increase, swashs
Living and can reduce, then the defect of crystals increases, and the particle participating in diffusion is also increased by, thus solid phase is anti-
Should accelerate, product increases, and constant temperature time is the longest, the thickness of conversion zone increase thus when extending constant temperature
Between, product can be made to increase.For ensureing that gangue can fully burn when burning, the gangue chosen
Particle diameter is 5cm, ensures that calcining heat raises 100 DEG C per hour, because solids bulk before calcination is one during calcining
Rise, with the presence of a large amount of spaces, along with the raising of calcining heat, start between granule produce bonding and reset, greatly
Fading away in space, temperature raises again, and the intergranular point cantact of intergranular point cantact is expanded into face contact gas
Hole is more and more less, and may finally get rid of pore, i.e. gradually rising along with temperature, intensity and density also by
Gradually improving, this is favorably improved the quality of produced molding sand.
It is ground into, when gangue after calcining is cooled to 25 DEG C, the granule that fineness is 60 mesh again.
Embodiment three
Choose the gangue that the mass fraction containing silicon dioxide and aluminium sesquioxide is 90%, and contained dioxy
The weight ratio of SiClx and aluminium sesquioxide is 0.85, because of mullite number be good and bad most important of molding sand grog
Mark, and the molecular formula of mullite is 3Al2O3·2SiO2, so selecting before gangue is calcined
Take, to ensure the quality of fluid origin molding sand.
Because the calcining heat of gangue is the key factor forming mullite, only when temperature is higher than 1100 DEG C
Just having mullite to generate, when temperature reaches 1400 DEG C, the formation speed of mullite compares very fast, when temperature liter
High to the yield of mullite when 1600 DEG C substantially without significant change.When calcining heat reaches 1600 DEG C, then protect
Temperature 2.5h, such mullite produces and substantially tends towards stability, because the motion that temperature raises particle can increase, swashs
Living and can reduce, then the defect of crystals increases, and the particle participating in diffusion is also increased by, thus solid phase is anti-
Should accelerate, product increases, and constant temperature time is the longest, the thickness of conversion zone increase thus when extending constant temperature
Between, product can be made to increase.For ensureing that gangue can fully burn when burning, the gangue chosen
Particle diameter is 6cm, ensures that calcining heat raises 120 DEG C per hour, because solids bulk before calcination is one during calcining
Rise, with the presence of a large amount of spaces, along with the raising of calcining heat, start between granule produce bonding and reset, greatly
Fading away in space, temperature raises again, and the intergranular point cantact of intergranular point cantact is expanded into face contact gas
Hole is more and more less, and may finally get rid of pore, i.e. gradually rising along with temperature, intensity and density also by
Gradually improving, this is favorably improved the quality of produced molding sand.
It is ground into, when gangue after calcining is cooled to 30 DEG C, the granule that fineness is 80 mesh again.
The present invention is not limited to above-mentioned preferred forms, and anyone can draw it under the enlightenment of the present invention
His various forms of products, no matter but in its details, make any change, every have same as the present application or
Akin technical scheme, within all falling within protection scope of the present invention.
Claims (8)
1. the technique using gangue casting sand, it is characterised in that comprise the following steps:
(1) gangue is chosen；
(2) by the calcined coal gangue chosen in step (1) to 1400-1500 DEG C, and it is incubated a period of time；
(3) gangue after calcining is pulverized, obtain molding sand.
The technique of use gangue casting sand the most according to claim 1, it is characterised in that step
(1) the gangue cast moulding that the mass fraction containing silicon dioxide and aluminium sesquioxide is 40%-90% is chosen in
Sand.
The technique of use gangue casting sand the most according to claim 2, it is characterised in that dioxy
SiClx is 0.25-0.85 with the weight ratio of aluminium sesquioxide.
The technique of use gangue casting sand the most according to claim 1, it is characterised in that step
(1) particle diameter of the gangue chosen in is 4-6cm.
The technique of use gangue casting sand the most according to claim 1, it is characterised in that step
(2) described in, the heating rate of calcining is 80-120 DEG C/h.
The technique of use gangue casting sand the most according to claim 1, it is characterised in that step
(2), in, the time of described insulation is 2-2.5h.
The technique of use gangue casting sand the most according to claim 1, it is characterised in that step
(3) described in, the gangue after calcining is first cooled to 20-30 DEG C, then pulverizes.
The technique of use gangue casting sand the most according to claim 1, it is characterised in that step
(3) particle diameter of molding sand described in is 40-80 mesh.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610168398.9A CN105798223A (en) | 2016-03-23 | 2016-03-23 | Technology for casting molding sand through coal gangue |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610168398.9A CN105798223A (en) | 2016-03-23 | 2016-03-23 | Technology for casting molding sand through coal gangue |
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| Publication Number | Publication Date |
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| CN105798223A true CN105798223A (en) | 2016-07-27 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610168398.9A Pending CN105798223A (en) | 2016-03-23 | 2016-03-23 | Technology for casting molding sand through coal gangue |
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| CN (1) | CN105798223A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111906244A (en) * | 2020-08-14 | 2020-11-10 | 湖南鑫恒环境科技有限公司 | Process for casting molding sand by using coal gangue |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1103338A (en) * | 1993-12-02 | 1995-06-07 | 煤炭科学研究总院西安分院 | Method for rejection of cristobalite in precision casting sand and refractory |
| CN1382539A (en) * | 2002-04-08 | 2002-12-04 | 淮北金岩高岭土开发有限责任公司 | Process for preparing mullite-type snad for precision casting by calcining coal-series kaolinite |
| US20060151145A1 (en) * | 2003-06-12 | 2006-07-13 | Karl Koch | Method for the production of a core sand and/or molding sand for casting purposes |
| CN103480793A (en) * | 2013-08-26 | 2014-01-01 | 安徽金岩高岭土科技有限公司 | Precision-casting surface-layer sand powder processed from coal series kaolinite |
| CN104057015A (en) * | 2014-05-28 | 2014-09-24 | 安徽鑫润新型材料有限公司 | Casting molding sand for non-ferrous metal and preparation method of casting molding sand |
-
2016
- 2016-03-23 CN CN201610168398.9A patent/CN105798223A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1103338A (en) * | 1993-12-02 | 1995-06-07 | 煤炭科学研究总院西安分院 | Method for rejection of cristobalite in precision casting sand and refractory |
| CN1382539A (en) * | 2002-04-08 | 2002-12-04 | 淮北金岩高岭土开发有限责任公司 | Process for preparing mullite-type snad for precision casting by calcining coal-series kaolinite |
| US20060151145A1 (en) * | 2003-06-12 | 2006-07-13 | Karl Koch | Method for the production of a core sand and/or molding sand for casting purposes |
| CN103480793A (en) * | 2013-08-26 | 2014-01-01 | 安徽金岩高岭土科技有限公司 | Precision-casting surface-layer sand powder processed from coal series kaolinite |
| CN104057015A (en) * | 2014-05-28 | 2014-09-24 | 安徽鑫润新型材料有限公司 | Casting molding sand for non-ferrous metal and preparation method of casting molding sand |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111906244A (en) * | 2020-08-14 | 2020-11-10 | 湖南鑫恒环境科技有限公司 | Process for casting molding sand by using coal gangue |
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Application publication date: 20160727 |
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