南非铬矿砂(AFS 40-50)

铬矿砂AFS 40-50(Chromite sand AFS 40-50)是一种黑色、具有半金属光泽得铸造砂。它来自于自然界中的铬铁矿。铬矿砂莫氏硬度5.5-6.5，比重4.3-4.8g/cm3。天然的铬铁矿石由尖晶石和脉石相两部分组成，两者通常是伴生的。尖晶石为 Mg·FeO Al Cr2O3,脉石为蛇纹石 H4 Fe·Mg3 Si2O9（水化硅镁），铬矿石中还有少量的镁橄榄石、石英、绿辉石等形态。其中的石英(SiO2）对铸造用的铬矿砂是有害的，需要通过加工手段去除。

Chromite sand AFS 40-50 is a black casting sand with a semi metallic luster. It comes from chromite ore in nature. Chromite sand has a Mohs hardness of 5.5-6.5 and a specific gravity of 4.3-4.8g/cm3. Natural chromite ore is composed of two parts: spinel and gangue, which are usually associated. Spinel is Mg • FeO Al Cr2O3, gangue is serpentinite H4 Fe • Mg3 Si2O9 (hydrated silicon magnesium), and there are also small amounts of magnesium olivine, quartz, green pyroxene and other forms in chromite. The quartz (SiO2) in it is harmful to the chromite sand used in casting and needs to be removed through processing methods.

铬矿砂AFS 40-50(Chromite sand AFS 40/50)的性能特点

(1)铬铁矿铸造砂Chromite sand具有优良的激冷特性，这种特性不减少热裂，但能影响温度梯度，促进方向性凝固而不需用冷铁。这个特性对大型厚壁铸件很重要，它可以促进铸件按顺序凝固，减少气孔缺陷。

(2)铬矿砂Chromite ore sand是惰性的，因而不和其它金属氧化物发生反应。它不被锰钢水润湿。锰钢铸件能很成功的使用铬铁矿砂。如果铸型是正常地刷涂料并且氧化硅含量低，则没有铁橄石反应。

(3)铬铁矿砂的线膨胀小，而线膨胀是一个可能引起夹砂铸件的因素。因此它可能用来混制大型铸件用的湿砂型。

(4)铬矿砂Chromite sand通过细粒烧结，伴随着激冷作用和高残留热强度，消除了金属渗透，减少了化学粘砂的风险。

(5)铬铁矿砂兼容性强，它可与各种粘结剂共同使用，同时它可属于某一的粒度范围。铬矿砂还可以与硅砂混合使用。

(6)铬铁矿砂的硅含量低，清理铸造砂时可以减少硅粉尘的摄入，不会对人体产生健康影响。

(1) Chromite sand for steel casting has excellent quenching properties, which do not reduce hot cracking but can affect temperature gradients and promote directional solidification without the need for cold iron. This characteristic is important for large thick walled steel castings. Chromite sand can promote sequential solidification and reduce porosity defects.

(2) Chromite ore sand is inert and therefore does not react with other metal oxides. It is not wetted by manganese steel water. Manganese steel castings can successfully use chromium iron ore sand. If the mold is coated normally and the silicon oxide content is low, there is no iron olivine reaction.

(3) The thermal expansion of chromite sand is small. Linear expansion is a factor that may cause sand inclusion in castings. Therefore, it may be used to mix wet sand molds for large castings.

(4) Chromite sand is sintered through fine-grained sintering, accompanied by quenching and high residual heat strength, eliminating metal penetration and reducing the risk of chemical sand sticking.

(5) Chrome ore sand has strong compatibility and can be used together with various binders, while also belonging to a certain particle size range. Chromite sand can also be mixed with silica sand for use.

(6) The silicon content of chromite sand is low, and cleaning the casting sand can reduce the intake of silicon dust, which will not have a health impact on the human body.

铬矿砂AFS 40-50(Chromite sand AFS 40/50)的技术参数：

1.   化学成分

2.物理性能：

铬矿砂AFS 40-50(Chromite sand AFS 40/50)的应用范围：

1. 大型厚壁型铸件铸造：铬矿砂配合砂型铸造、呋喃树脂自硬砂、水玻璃自硬砂等工艺，用于体积重量大的铸铁件和铸钢件，可以使铸件按既定的顺序进行冷却，有利于提高铸件内部的紧密度，增强铸件的强度。此外，对于使用硅砂的工艺，可在容易出现气孔、脉纹的关键部位，使用铬矿砂作为面砂代替硅砂，可以有效防止裂纹、气孔等铸造缺陷。

2. 消失模铸造。在消失模铸造中，选用铬矿砂，可以防止石英砂铸造造成的夹砂、粘砂等缺陷。用于制造高铬铸钢、高锰钢材质的阀门、叶轮等铸件。

3. 壳型铸造：铬矿砂可用于壳型铸造中复杂部件的芯砂材料，制作砂芯。用于生产高精度、表面光滑的304，316不锈钢铸件和碳钢精密铸件等，可以有效防止铸件内腔的粘砂问题。

4. 砂型铸造：铬砂还可以用于砂型铸造，如型砂铸造、水玻璃自硬砂砂型铸造等，用于生产各种大中小型零件，如泵体、管道、阀门等。

1. Large scale thick walled casting: Chromite sand combined with sand casting, furan resin self hardening sand, water glass self hardening sand and other processes are used for large volume and weight cast iron and steel castings. It can cool the castings in a predetermined order, which is conducive to improving the internal tightness of the castings and enhancing their strength. In addition, for the process of using silica sand, chromite ore sand can be used as surface sand instead of silica sand in key areas where porosity and veins are prone to occur, which can effectively prevent casting defects such as cracks and porosity.

2. Lost foam casting. In lost foam casting, using chromite sand can prevent defects such as sand inclusion and sticking caused by quartz sand casting. Used for manufacturing castings such as valves and impellers made of high chromium cast steel and high manganese steel materials.

3. Shell casting: Chromite sand can be used as a core sand material for complex components in shell casting, making sand cores. Used for producing high-precision, smooth surface 304316 stainless steel castings and carbon steel precision castings. It can effectively prevent the problem of sand sticking in the inner cavity of castings.

4. Sand casting: Chromite sand can also be used for sand casting, such as sand casting, water glass self hardening sand casting, etc., to produce various large, medium, and small parts, such as pump bodies, pipelines, valves, etc.

铬矿砂AFS 40-50(Chromite sand AFS 40/50)的粒度分布如下：

铬矿砂Chromite sand的其他型号：

国内常规粒度：10-20目 20-40目，20-60目，30-70目，40-70目，50-100目、70-140目，140-270目 0-1mm 200目，325目,400目，70#-0
出口常规粒度：AFS 25-35 AFS 25-30 AFS 30-35 AFS 35-40 AFS 40-45 AFS 45-50 AFS 40-50 AFS 50-55 AFS 55-60 AFS 60-65 0-1mm 200# 325#,400#