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Why should South Africa chrome ore be used for casting

 Mineral products mainly include South African foundry grade, chemical grade, refractory grade, metallurgical grade chrome ore, Indian refractory and metallurgical grade chrome ore, Philippines chrome ore and other ore products from many countries. Among them, South African foundry-grade chrome ore sells well in more than 20 provinces and cities across the country and has won wide acclaim from the industry. Now let the editor of Dalian Jintuo Company give you a detailed introduction to why chromite sand is popular.

Why should South Africa chrome ore be used for casting

Application of chromite sand in foundry

Chromite sand belongs to the chromium spinel group. The main mineral composition is FeO·Cr2O3. The actual mineral is composed of a mixture of various spinels.

The density of chromite sand is 4-4.8g/cm3, the Mohs hardness is 5.5-6, and the refractoriness is >1900°C.

The main properties of chrome ore

  • (1) Chrome ore has good resistance to alkaline slag and does not react with iron oxide, etc.; therefore, in practical applications, chromium ore can avoid thermal and chemical sticking of sand;
  • (2) During the molten metal sand casting process, the chromium ore itself undergoes solid phase sintering to prevent the penetration of molten metal, thereby preventing mechanical sand sticking;
  • (3) The thermal conductivity of chromium ore sand is several times larger than that of silica sand, which can increase the cooling rate of castings. Therefore, chromium ore sand can play the role of external cold iron in practical applications;
  • (4) The most harmful impurity in chromium ore is carbonate (CaCO3·MgCO3), which decomposes CO2 when it comes in contact with high-temperature metals, which is easy to cause porosity in the casting; usually, chromium ore containing carbonate is passed through It is roasted at 900°C—950°C to decompose the carbonate.
  • (5) The influence of the particle size of chrome ore on its refractoriness The particle size of chrome ore can significantly affect its refractoriness. In the past, it was believed that too coarse particle size would reduce the surface finish of castings. However, the surface of sand molds and cores made of chrome ore are usually sprayed with a certain thickness of paint, so that the surface finish of the die castings is hardly affected.

Generally, the suitable size of the sand mold used for large-scale steel casting is 40/70 mesh, and the size of the sand used for medium and small parts is 50/100 mesh. There are also special circumstances such as: some small water pump industries, considering economic factors, use chromium ore instead of zirconium sand. The chromium ore purchased by these factories is required to be very fine, requiring 70/140 mesh, or even 100/200 mesh, and so on.

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What Is PTJ?
PTJ adopts flexible manufacturing methods to help our customers to control the product cost but best quality guranteed. Some frequently used machining processes include CNC milling, CNC turning, precision grinding, EDM machining, laser cutting, welding, CNC punching, sheet metal stamping, profile extrusion, die casting, forging, and more. Most of the custom precision cnc machining china parts and plastic machining components we made are related to automation machines, robotics, medical devices, fiber optics, aerospace/aircraft, test and measurement, sensors, telecom components, scientific devices, audio equipments, bicycles, boats, camera, cars, drones, electronic enclosures, front panels, furniture and architecture hardware, lighting, motorcycles, scooters, utv, jeeps, trucks, sports equipments, machinery, music instruments, and so on.
For Surface Finishes
Thanks to our mature supplier management and continuously experience accumulation. Now we have very stable surface finish suppliers to assist us to do different surface finishes with stable and excellent quality. Some Frequently used surface finishes are Anodizing, Oxide, Nickel Plating, Chrome Plating, Gold / Silver Plating, Powder Coating, Zinc Plating, PVD Coating, Passivation, Heat Treatment, Electrochemical machining, Brushing, Polishing, Sandblasting, etc.
General Tolerance of Equipments
1. CNC Milling tolerance: +/-0.01mm
2. CNC turning tolerance: +/-0.01mm
3. Precision grinding tolerance: +/-0.005mm
4. EDM machining tolerance: +/-0.005mm
How to Control Quality?
1. Inspection by machinist himself who is responsible for a specific part machining.
2. First article part inspection by QA.
3. IPQC patrol inspection during production.
4. PQC inspection before shipping according to ISO9001 sampling inspection standard for large quantity production. And for small quantity, 100% full inspection.
5. Material Certificates and outgoing inspection reports could be provided.
Our CNC machine and swiss machining shop sets full and advanced inspection instruments such as CMM, projector, height instrument, industrial microscope, micrometer, calipers, thread gauges, pin gauges, block gauges, etc. so as to inspect all details on drawings and confirm quality is good and issue the ourgoing reports accordingly.
How to Start Working with Our Company?
1) Sending detailed RFQ with 2D and 3D drawings to through email to info@pintejin.com. General drawing formats like PDF/ STEP/IGES/X_T etc are accepted.
2) We check and confirm about materials, surface finish and quantiy, and evaluate. If any question, our sales engineer would double check with customers until everything is clear. We will quote accordingly if we are ok to make the parts with best quality. If no question and everything is clear, we send quotation with best prices within 24 hours. Our sales engineer team is online for 7/24 for offering customers the best cnc machining services.
3) We recommend to start from few pcs prototypes for approval at the beginning. If nothing wrong after customer’s test and approval, then we proceed to volume cnc manufacturing.
Some Tips for Customers
a. We accept Paypal payment of small amount payment for samples or small batch orders for building mutual trust at the beginning. General payment terms is 30% by wire transfer, and balance before shipping.
b. Delivery time for few pcs samples are generally 5 to 7 days, and 15 to 25 days for volume production. If the order quantity was too big, we would check and confirm delivery time sepertely.
c. Our company has concrete promise to all customers that if any quality problem caused by our factory, we would remake all parts for free or send money back.
Safe Packing Methods to Prevent Goods from Damage during Transportation
Due to long distance transportation to overseas countries, safe and strong packing is very important to gurantee the parts to be in good conditions when arriving at customer’s hand. We choose different packing materials according to different parts and quantity. Some commonly used packing materials are pp/bubble bag, oil paper, foam, blister tray, 5 layer carton, wood box, etc. See below some packing pictures.