CN108356214A

CN108356214A - Green moulding sand additive and its application method

Info

Publication number: CN108356214A
Application number: CN201810412944.8A
Authority: CN
Inventors: 牛文峰; 李祖来
Original assignee: Yunnan Heng Weft Technology Co Ltd
Current assignee: Yunnan Heng Weft Technology Co Ltd
Priority date: 2018-05-03
Filing date: 2018-05-03
Publication date: 2018-08-03

Abstract

The present invention relates to foundary industry field, especially a kind of green moulding sand additive and its application method.The green moulding sand additive of the present invention is mixed in mass ratio by following raw materials：SiO₂50~85%、Al₂O₃ 9~45%、MgO 0.2~3%、Fe₂O₃1~8%、CaO 1~7%、Fe₃O₄0.5~8%.Combustion reaction is not occurring for the additive, is generated without toxic and harmful gas in casting process, belongs to pollution-free, contribute to the green material of energy-saving and emission-reduction.It is mainly used for substituting the organics additives such as the coal dust used in conventional wet type casting, which has excellent anti-stick grittiness energy, reduce the wetability of casting mold and molten metal, improve the surface quality of casting.

Description

Green moulding sand additive and its application method

Technical field

The present invention relates to foundary industry field, especially a kind of green moulding sand additive and its application method.

Background technology

In casting industry, molding sand is the material for being used for moulding in casting.Molding sand is generally bonded by foundry sand, molding sand The Modeling Materials such as agent and additional thing mix according to a certain percentage, it is also possible to natural silica sand argillaceous.

Molding sand has extremely important effect, the casting wasted product caused by the unstable quality meeting of molding sand in Foundry Production Rate increases.Usually the performance indicator of molding sand is required to have:Gas permeability, intensity, deformability, collapsibility, mobility etc..In order to improve Surface quality of continuous castings reduces casting flaw, additional thing is often inserted in molding sand in casting process.In casting process, molten Melt after molten metal pours into casting mold, the organic matter in additional thing will produce imperfect combustion and pyrogenetic reaction, casting mold will produce and Give off poisonous and harmful substance, common additional thing is coal dust both at home and abroad at present, have the cost of material is low, Sand sticking-resistant effect compared with Advantage good, production efficiency is high, but its consumption is big, discharge is serious, coal dust firing decomposition has poison gas in casting process Body and carcinogen, pollute environment, influence worker's health.According to statistics, casting is produced using coal dust clay-bonded sand, it is per ton Casting need to consume 0.8t ~ 1t or so molding sand, and the whole nation will discard a large amount of old sands every year, while consume fresh sand of the number in terms of ten million ton, The especially coal dust clay old sand of ironcasting casting, serious black pollution is brought to environment, is not suitable with foundary industry science hair The needs of exhibition, do not meet the Environment Protection Policy and national Ecological Civilization Construction of current consumption reduction emission reduction requirement its to foundry worker Health and ambient enviroment generate harmful effect.

With the increase of economical and environmentally friendly pressure, foundary industry field has been working hard find new material substitution containing organic The additive of material to meet the requirement of environmental protection and occupational health, while can also reduce production cost.Currently, substituting coal dust Anti-burnon new material research become both at home and abroad casting expert emphasis research topic, wherein inorganic composite materials additive because its Toxic and harmful gas is not generated in casting process, and there are preferable effect, while its raw material to improving surface quality of continuous castings It derives from a wealth of sources, it is cheap, become instantly popular one of research direction.

Invention content

It is an object of the invention to be directed to the existing heavy-polluted defect of coal dust additive, a kind of moulding sand additive, nothing are provided Pollution, and there is excellent anti-stick grittiness energy, improve the surface quality of casting.

The invention discloses a kind of green moulding sand additives, are mixed by mass percentage by following raw materials：SiO₂50~ 85%、Al₂O₃ 9~45%、MgO 0.2~3%、Fe₂O₃1~8%、CaO 1~7%、Fe₃O₄0.5~8%。

The application method of heretofore described moulding sand additive is as follows：The casting that mass percent is 80 ~ 90% is chosen to use Sand, 4 ~ 12% bentonites, 5 ~ 10% moulding sand additives, 2 ~ 6% water stand 1 ~ 6 minute after then mixing above-mentioned material, then will Mixture is put into sand storage bin, then moulding, casting metals liquid, waits for casting cooled and solidified, isolated finished product cast.

The moulding sand additive of the present invention has following features：

（1）The additive raw material sources of the present invention are extensive, and preparation process is simple, at low cost, and production efficiency is high.

（2）One layer of nucleocapsid can be formed in casting process with the molding sand of this additive simultaneously, reduce molten metal and The wetability of molding sand prevents the generation of scab, and requirement of the additive to moisture is relatively low, can reduce the probability of stomata generation, Finally so that cast(ing) surface is smooth, quality is good.

（3）The discharge of the pernicious gases such as benzene, dimethylbenzene and sulfur dioxide is reduced, it is environment-protecting and non-poisonous, pollution-free.

（4）Additive belongs to inorganic composite materials, does not burn, and transports and stores and is safer.

（5）The molding sand recycling effect that this additive is added is good, reduces old sand discharge, reduces Foundry Production cost.

Description of the drawings

Fig. 1 is that the SEM of moulding sand additive of the present invention schemes.

Specific implementation mode

Below by way of specific embodiment, invention is further described in detail, but protection scope of the present invention is not limited to The content

Embodiment 1：

SiO is taken in mass ratio by metering device₂70%、Al₂O₃ 25%、MgO 0.5%、Fe₂O₃2%、CaO 2%、Fe₃O₄0.5% It is uniformly mixed, prepares 1000 kilograms of total amount, be packed into packaging bag.

In a Foundry Works, taken in mass ratio by metering device foundry sand 80%, bentonite 8%, moulding sand additive 7%, Water 5% is mixed 3 minutes, mixture is put into sand storage bin after mixed, hand moulding, casting metals liquid, refrigerated separation is obtained into Product casting, cast(ing) surface do not have scab, casting not to have other defects.It has persistently used 3 months.

Embodiment 2：

SiO is taken in mass ratio by metering device₂55%、Al₂O₃ 35%、MgO 3%、Fe₂O₃4%、CaO 2%、Fe₃O₄1% mixing Uniformly, 10000 kilograms of total amount is prepared, packaging bag is packed into.

In a Foundry Works, taken in mass ratio by metering device foundry sand 85%, bentonite 6%, moulding sand additive 5%, Water 4% is mixed 2 minutes, mixture is put into sand storage bin after mixed, microseism squeeze mo(u)lding line, casting metals liquid, and cooling 2 is small When, isolated finished product cast, cast(ing) surface is smooth, and casting quality is qualified.It has persistently used 2 months.

Embodiment 3：

SiO is taken in mass ratio by metering device₂65%、Al₂O₃ 25%、MgO 1.2%、Fe₂O₃1.3%、CaO 7%、Fe₃O₄ 0.5% is uniformly mixed, and prepares 10000 kilograms of total amount, is packed into packaging bag.

In a Foundry Works, foundry sand 83.5%, bentonite 7%, moulding sand additive are taken in mass ratio by metering device 6%, water 3.5% is mixed 90 seconds, mixture is put into sand storage bin after mixed, horizontal parting removable-flask moulding line, casting metals liquid, 1 hour cooling, isolated finished product cast, cast(ing) surface is smooth, and casting quality is qualified.It has persistently used 4 months.

As shown in Figure 1, from the scanning electron microscopic picture of green moulding sand additive of the invention, it can be seen that the additive is microcosmic Pattern is reunited by a large amount of fine particles, shows porous structure, and such morphosis is conducive to gas in casting process Discharge, while forming one layer of shell-like structure with the interactions such as molding sand at high temperature, prevent molten metal from infiltrating molding sand, to Stomata is effectively reduced, the generation probability of the casting flaws such as scab improves the surface quality of casting.

Claims

1. a kind of green moulding sand additive, is mixed by mass percentage by following raw materials：SiO₂50~85%、Al₂O₃ 9~ 45%、MgO 0.2~3%、Fe₂O₃1~8%、CaO 1~7%、Fe₃O₄0.5~8%。

2. the application method of type green sand additive as described in claim 1, it is characterised in that specific as follows：Choose quality percentage Than foundry sand, 4 ~ 12% bentonites, 5 ~ 10% moulding sand additives, 2 ~ 6% water for 80 ~ 90%, above-mentioned material is then mixed 1 ~ 6 Minute, then mixture is put into sand storage bin, then moulding, casting metals liquid, waits for casting cooled and solidified, isolated finished product Casting.