Crushing Material

32:

• An apparatus for crushing material that includes an upstream pair of crushing rolls defining a nip therebetween for receiving feed material and crushing the feed material to a first particle size range and for forcing crushed material from the nip, a downstream pair of crushing rolls having a nip therebetween for receiving crushed material from the upstream pair of rolls and crushing the feed material further to a second particle size range, and a transfer chute extending between the upstream and downstream pairs of rolls and confining crushed material from the upstream pair of rolls to move to the downstream pair of rolls, whereby in use of the apparatus, crushed material from the upstream pair of rolls forms a feed of material for the downstream pair of rolls as it moves through the transfer chute to the downstream pair of rolls.

33:

• The apparatus defined in claim 32, adapted to form a pressurised feed of material moving through the transfer chute from the upstream pair of rolls to the downstream pair of rolls.

34:

• An apparatus for crushing material that includes at least one pair of crushing rolls that is adapted for intermittent rotation roll operation and defining a nip therebetween for receiving feed material and crushing the feed material to a first particle size range and for forcing crushed material from the nip.

35:

• The apparatus defined in claim 34, wherein the pair of crushing rolls is adapted for stepped rotation roll operation.

36:

• The apparatus defined in claim 34 which includes a stepping motor system for operating the pair of crushing rolls on a stepped rotation basis.

37:

• The apparatus defined in claim 34, which includes a downstream pair of crushing rolls having a nip therebetween for receiving crushed material from the said pair of crushing rolls, hereinafter referred to as the “upstream” pair of rolls, and crushing the feed material further to a second particle size range, and a transfer chute extending between the upstream and the downstream pairs of rolls, whereby in use of the apparatus, crushed material from the upstream pair of rolls forms a feed of material for the downstream pair of rolls as it moves through the transfer chute towards the downstream pair of rolls.

38:

• The apparatus defined in claim 37, adapted to form a pressurised feed of material moving through the transfer chute from the upstream pair of rolls to the downstream pair of rolls.

39:

• The apparatus defined in claim 32 or claim 37, wherein the downstream pair of rolls is adapted for intermittent, such as stepped, rotation roll operation.

40:

• The apparatus defined in claim 32 or claim 37, wherein the pressurised feed of material for the downstream pair of rolls is in the form of a moving packed bed of material in the transfer chute.

41:

• The apparatus defined in claim 40, wherein, in use of the apparatus, the downstream pair of rolls is choke fed from the upstream pair of rolls.

42:

• The apparatus defined in claim 32 or claim 34, which includes more than two pairs of rolls, with each pair of rolls successively crushing the material.

43:

• The apparatus defined in claim 32 or claim 34, wherein, when there are only two pairs of rolls, the downstream pair of rolls is adapted to produce crushed material that has a particle size range that can be conveyed by gas or liquid in a pipeline.

44:

• The apparatus defined in claim 32 or claim 34, wherein, in the case of an underground metalliferous mine, the top size of the feed material for the upstream pair of rolls is of the order of 90 mm for smooth rolls and of the order of 60 mm for studded rolls, the crushed material produced in the upstream pair of rolls is 5-10 mm, and the crushed material produced in the downstream or the most downstream pair of rolls is less than 2 mm.

45:

• The apparatus defined in claim 32 or claim 34, which includes a pre-crushing means, such as jaw or gyratory crushers, for pre-crushing feed material to form the feed material for the pair of rolls in situations where there is one pair of rolls only or to the upstream pair of rolls in situations where there are two or more pairs of rolls.

46:

• The apparatus defined in claim 32 or claim 34, which includes a means for exposing feed material to microwave energy for physically and/or chemically altering the material prior to supplying the feed material to the pair of rolls in situations where there is one pair of rolls only or to the upstream pair of rolls in situations where there are two or more pairs of rolls.

47:

• The apparatus defined in claim 32 or claim 34, which includes a means for exposing crushed material flowing between upstream and downstream pairs of rolls to microwave energy for physically and/or chemically altering the crushed material.

48:

• An apparatus for crushing material and thereafter transporting the crushed material to another location which includes the crushing apparatus defined in claim 32 or claim 34 and a conveying means for conveying the crushed material (a) from the pair of rolls to another location in situations where there is one pair of rolls only, (b) from the downstream pair of rolls to another location in situations where there are only two pairs of crushing rolls or (c) from the most downstream pair of rolls to another location in situations where there are more than two pairs of rolls.

49:

• The apparatus defined in claim 48, wherein the crushing apparatus includes a means for feeding crushed material from the downstream or the most downstream pair of rolls into the conveying means.

50:

• The apparatus defined in claim 49, wherein the feed means is adapted to feed crushed material continuously into the conveying means.

51:

• The apparatus defined in claim 50, wherein the continuous feed means includes a screw feeder.

52:

• The apparatus defined in claim 48, wherein the conveying means includes a pipeline and a means for establishing a flow of gas or liquid through the pipeline for conveying crushed material in the pipeline.

53:

• The apparatus defined in claim 48, wherein the conveying means includes a means for separating the crushed material and the conveying gas or liquid at the other location.

54:

• A method of crushing material that includes steps of supplying a feed material to a nip between an upstream pair of crushing rolls and crushing the feed material to a first particle size range and producing a feed of crushed material and supplying the feed to a nip between a downstream pair of crushing rolls and crushing the feed material to a second particle size range.

55:

• The method defined in claim 54, which includes producing a pressurised feed of crushed material in the upstream pair of crushing rolls.

56:

• The method defined in claim 54, which includes crushing the feed material successively in more than two pairs of crushing rolls.

57:

• The method defined in claim 54, which includes a step of supplying the crushed material from the downstream pair of rolls into a pipeline and conveying the material through the pipeline to another location for stockpiling and/or further processing the material.

58:

• A method of crushing material that includes the steps of supplying a feed material to a nip between a pair of crushing rolls rotating intermittently, such as in a series of steps, and crushing the feed material to a first particle size range and producing a feed of crushed material.

59:

• The method defined in claim 58, which includes producing a pressurised feed of crushed material in the pair of rolls.

60:

• The method defined in claim 58, which includes supplying the feed from the pair of rolls, i.e., the upstream pair of rolls, to a nip between a downstream pair of crushing rolls and crushing the feed material to a second particle size range.

61:

• The method defined in claim 58, which includes crushing the feed material successively in more than two pairs of crushing rolls.

62:

• The method defined in claim 58, which includes a step of supplying the crushed material from the (a) single roll pair in situations where there is one pair of rolls only, (b) the downstream roll pair in situations where there are two roll pairs only, or (c) the most downstream pair of rolls in situations where there are more than two roll pairs, into a pipeline and conveying the material through the pipeline to another location for stockpiling and/or further processing the material.