How to use grinding ball metal mould and sandbox metal mould?

The manual grinding media balls metal mould (producing balls size from dia30-150mm) and sandbox metal mould (producing balls from dia8-30mm) are widely welcome foundries home and abroad. It can produce low , medium and high chrome balls with different composition. 

The advantages: investment costs are low; easy operating; high production efficiency; 

Here are detailed using instruction of how to use the metal mould to manufacture? 

For dia30-150mm grinding media balls metal mould 

  1. Heating: The metal mould should be heated before using .when its temperature ups around 200-300degrees, then can start to pour. Or the metal mould will be easily hurt. 
  2. Sand Molding: After heating, the top and bottom metal mould should be filled with common sand.  A hole is needed in the middle of the top mould so that the molten iron can be filled inside.  
  3. Mould Ball Core Painting: After the sand molding,  the ball core of the metal mould should be protected with acetylene through spay smoke or using high-temperature painting. In this way, can lengthen the mould’s life and enhance balls quality. 
  4. Casting: The top mould and the bottom mould should be closed after protecting. Then with the help of pouring ladle, pouring the molten iron into the mould. 
  5. Open mould:  After several minutes, we should open the mould with the help of two round bars to respectively insert the holes on the surface of mould, and then get the balls out. Then re-mould and re-cast .
  6. Sand ratio: 100kg common sand equipped with 20kgs clay and 8-12kgs water glass, and the put them into sand mixer machine to crush down.

Key tips:

√ First, Heating the mould properly is vital.

 The cold metal mould should be HEATED before fully pouring for the first time using. Some clients made mistakes and damaged the mould. So if heating the moulds is a little bit difficult, then you can do like following: after sand molding finishing and closed the top and the bottom mold, first time pouring, please ONLY  Pouring the HALF FULL  of the molten iron into the metal mold. Let the molten iron’s temperature heated the metal mold. Then get the half balls out, and for the second time pouring, fill fully.

√ Second, protecting process results in the working life of the metal mould.

You can choose acetylene or special painting to coated on the surface of ball cores. It’s better to do this protection every day.

√ Third, after finishing the works every day, the operators should fill the sand inside of the mold.

Do like this,  when the next day coming, directly pouring the molten iron in and no need to heat the metal molds again.

√ Fourth, metal mould heated again. 

If the molds long time no use and the environment is wet, then when reusing, even already fill the sand inside of the molds, still need to heat again, Or you will hear little noise like small fireworks. And the ball’s quality is bad.

If you still met some other problems or matters, welcome you contact us. 

For sandbox metal mould (Dia8mm – 30mm)

  • There are one pair of the sandbox metal mould and one piece of the pattern for using. Please note that the pattern has TWO sides, top and bottom.
  • First, filling the sand with top and bottom sandbox mould. Put the bottom sandbox mould on the bottom side of the pattern,  filling the mixed sand in, then using a human-made flat hammer to tightn the sand.
  • Using the same method to make sand mooulding for the top side of the sandbox with the top side of the pattern. This is very important. We can not only use one side of the pattern to make both top and bottom mould.
  • Closed the top and bottom sandbox mould.  
  • Using a pipe to make two holes on the pouring gate position on the top sand. This hole is used to pour the molten iron. 
  • Sand ration: 30kgs bentonite, 70kgs common sand, 5-8kgs coal power; some water. 
patterns for grinding balls metal mould