To Save Fine Gold from Sand.

To Save Fine Gold from Sand.

(By "Nugget.").

The. following information is given in reply to a correspondent (W. L. J.), who asks for every detail of the process of saving fine : gold from sand.
To save fine gold from sand is a matter which has puzzled miners in every country ever since gold was first mined, and in Australia and California it has taxed the ingenuity of mining men since, gold was first dug in those countries. Bearing the above remarks in mind; W. L. J. must not ; be disappointed if the following methods, generally adopted here and in America, are not in, his hands a complete success: If the wash stuff contains sand and gold only, it should not be difficult to save some of the gold, especially where it is plentiful; but if; as usually happens, the dirt also contains black sand (which may mean a variety of minerals, such as-tin, iron sand, etc.), the task will be more difficult. Where the wash dirt is merely gold and sand, a goodly proportion of the gold should be saved in a sluice-box, with, a blanket or some coir mat- ting in tho bottom; The inquirer presumably knows the use of the sluice-box, how to set it. and the quantity of water to apply to it. if not, the sluice-box should be at least 12 ft long (double or-treble that length would answer better where the gold is very fine). A sluice-box 12 ft long should be set; at a pitch of 1 in 12; place a false bottom in it, with a blanket or coir matting near the bottom end, turn on a head of water (say 4 in deep at the intake end), and shovel the sand into the intake end of the box, or about 2 ft below the intake end. Keep the .box running clear, i.e.. do not let the sard choke it up by running through in a. thick mud ; let one shovelful be washed away before another is dropped in. This is called "letting the box run clear," and by this process some portion of the gold should be saved. If the metal is in the form of very fine, float gold, perhaps no great portion might be saved in this way; but still the ground should be rendered payable by the method described..: In the event of. the sand, as is most likely, : containing a ; conglomeration of tin, iron, and other substances, other methods must be employed. On the West Coast of New Zealand, and on the northern sea beaches of New South Wales, various, devices have been employed to save the gold, but the principle of them all may be gathered from the description given here- under:
In New Zealand the black sand and gold was concentrated by any means within the reach of the miner-sometimes in sluice-boxes ; as described, and at other times; in the old-fashioned cradle; then the concentrates were placed in a barrel with beaters or agitators in it like a. churn, some . hot water and quicksilver were added, and the
whole briskly agitated. In this way ; the gold was amalgamated with the quicksilver, and the . black sand and other minerals left behind. - On the sea beaches of Northern New South Wales the miners have a very simple appliance for saving the .gold:, A box-shaped affair, about 4 ft high and 3 ft long and 2 ft 6 in wide, is made put of pine boards, with a hopper at the top. In this box which; is set on end are. fixed two, amalgamated copper plates at an angle of about 45 de'g. The, method of operation is this: A suitable locality is fixed upon where there is plenty of wash dirt or sand containing gold, and a small paddock or trench is opened on the seashore in a position where the sea water will drain into it. The box is then fixed in position, and a small plunger pump, made out of a zinc or iron tube and a rod and small plunger pump at the end, is laid at an angle, with the bucket end immersed in the water, and the discharge end laid over the hopper. Half a dozen shovelfuls of sand are laid on a small platform at the mouth of the hopper, and the operator then works the pump with one hand and pushes a portion of the sand into the hopper with the other. The sand and water, fall on the first plate, and in turn on to the second plate, which is set below the first at an opposite angle to receive the stuff, and Anally drop out of the box as tailings. Of course, when the free gold comes in contact with the amalgamated copper plates the gold is caught on them by the silver and held in position. The plate is cleaned of its gold contents perhaps once a week, or as often as necessary. It sometimes happens that the gold is coated with a material which prevents it from adhering to the plate. In such a case it would be necessary to treat the .wash in a solution of caustic soda, and roast it on a sheet of iron over a fire before sending it through the sluice box or apparatus described.

Taken From

Australian Town and Country Journal
January 1901
http://newspapers.nla.gov.au/