Box 0230

Scope and Contents

(Printed on photo in white “Diamond Ground Depositing Floor – DeBeers”) View showing Blue Ground deposited on floors for “weathering” The Blue is brought from the mines to these various floors, which are simply large areas of the veldt leveled off. Here it is dumped and allowed to remain for, from 3 to 6 months (depending on its hardness) exposed to the sun & rain. At the end of that period it is practically pulverized and is then re-loaded & conveyed to the washing machine.

Scope and Contents

(Printed on photo in white “De Beers Depositing Floors.”) View showing method of dumping the Blue on the floors, Each mine has its own floors, and the ground from the various mines is never mixed. The total area of all floors is about 4.500. acres. There are at present deposited on these floors about ten million tons of Blue Ground.

Scope and Contents

(Printed on photo in white “Depositing Floor – Steam Harrowing”) View showing method of harrowing the Blue during the weathering period. The Blue is constantly harrowed by means of heavy harrows drawn backwards 7 forwards over the floors by wire ropes operated by heavy traction engines. In this way fresh faces are presented to the air, and greatly increases the rapidity of dis-integration.

Scope and Contents

(Printed on photo in white “De Beers Floor”) View showing the process of re-loading Blue from the floors after “weathering.” The large lumps shown consist of large boulders of rock which are found embedded in the Blue, and extra hard lumps of Blue called “cylinder lumps.” After the pulverized ground has been Cleared up, the boulders are loaded & taken to the waste dump. The hard Blue lumps are taken to the Crushing Mill.

Scope and Contents The above view shows one of the numerous washing plants operated by The Company. The Blue is brought to the machine from the floors. The Blue is passed through crushers, sieves and screens, and is finally passed into the rotary washing pans. The concentrate from the pans containing the diamonds and other heavy substances, such as quartz, garnets, olivenes, etc., is tapped off at regular intervals and allowed to run into locked trucks standing beneath the pans. In these it is then...

Scope and Contents (Printed on photo in white “DeBeers Floors – Pulsator and Mill.) Crushing Mill on left, Pulsator on right. To the pulsator is conveyed the concentrate from the various washing machines in locked steel trucks hauled by small steam locomotives. The concentrate is then passed through Jigs, which separate everything from the Diamonds except the various heavy crystals associated with them. The concentrate from the jigs then passes over patent oscillating Grease Tables. It is the peculiar...

Scope and Contents

Views showing combined washing & crushing plant during erection. Blue is fed, first to large gyratory crushers, thence to crushing rolls, from rolls to screws oversize, back to rolls undersize to washing pans.

Scope and Contents

(Machinery similar to previous)

Scope and Contents

The above view shows the main crushing plant to which the cylinder lumps from the various floors are conveyed for treatment. After crushing, the Ground passes through the same process as the pulverized ground.

Scope and Contents

(Different view of previous)