Application and precautions of chromite sand in casting
Chromite sand is a naturally occurring spinel consisting primarily of the oxides of chrome and iron. It is a by-product of ferro-chrome production and is mainly used in foundry applications and in glass production.
一、Application of chromite sand in casting
Chromite sand is a special inorganic material in refractory,ceramics,casting fields.In casting,chromite sand is mainly used in the manufacturing of cast iron, cast steel and alloy castings.
It can improve heat resistance, hardness and wear resistance of sand molds and castings,meanwhile It can also be used for pouring and exhausting.
Using chromite sand,we can add it directly,or added mixed with other refractory.When casting temperature is higher 1200℃,chromite sand can be added directly,if lower than 1200℃,usually used together with refractory such as Gypsum, graphite etc.
二、Precautions of chromite sand in casting
- Operating temperature
We need pay more attention to operating temperature.Chromite sand will be oxidized during high temperature,then it is better that the chromite sand works under 1200℃.
- Oxidation tendency
Chromite sand is easy to be oxidized during casting.
- Volatility
Chromite sand is volatile,which is very harmful to workers and environment.Necessary protective measures should be taken when using chromite sand,eg. taking personal protective equipment such as protective masks and gloves.at the same time,chromite sand Cannot be exposed to air for a long time.
三、Solutions to problems of chrome ore in casting
- Oxidization
Chromtie sand is easy to be oxidized,which will make it expand.Usually the oxidation tendency of chromite sand can be reduced by adding redox agents, using inert sand, closed sand boxes, etc.
- Pre-processing
Chromite sand need be processed before casting,for example,adding acidifiers such as boric acid, oxalic acid, etc to reduce alkaline of chromite sand.
