THE MINER.

Cromwell Argus, Volume VII, Issue 316, 1 December 1875, Page 6

THE MINER.

gold saving fkom quartz. (By Reefer.)

Through your columns I wish to drawthe attention of the mining community (anc to those especially who have crushing machiiery in operation) to the old-fashioned and aburd manner of amalgamation generally emptyed. My terms may seem, harsh hut I canlhow they are nevertheless true. I mean the opper plated tables with amalgamation v the stamper boxes, —being the original iea in the Australian colonies on the first disOvery of reefs—alongside that of the Chiliai mill; and to stick to the old plan varicts expedients have been adopted, viz., odium amalgam, constant skimming of the jpples, daily and almost hourly clearing of plates, and burning of quartz—the latter he only satisfactory one when properly do© ; but even this, although so largely empoyed at the present, has failed to come up t a more simple method and perhaps partly a/iore oldfashioned one than either. Befoe I give my description, I will place beire your readers some of the reasons whiti call for immediate attention to this mat&r. Most Victorians of early date will remmber that very little difficulty was found tfcollectthe gold, after box amalgamation wasntroduced, and although a general loss w» known to take place, yet the system I hav referred to was fairly accepted • in the one r the other ; but after a time minerals in thediape of sulphurets and arsenites, antimon, galena, and others, which are purely and erectly antagonistic to amalgamation of goliKith mercury, forming in themselves a body- 10 destroy and swallow up quicksilver, oftenurning it into a substance like soft soap, andionsequently of no service whatever to deta* any gold that may come in contact witht. As a result what is not amalgamated inie stamper boxes has very little chance of .oing so outside, and having escaped the ;pples (for gold in this state will have no dHeulty in that) it finds its way into the things heap, or into the bed of some inacc<sible river. Now, none of us who have wfked both Victorian and New Zealand rees especially those in our Province, can bu' admit that our reefs are far more than those of the former, and consequ<i% we have greater need to reform ourtystem of saving gold. The late visit of th/most scientific mining

maft of Victoria among us seoms to have failed in this particular to leave any impression as far as [ know or read of. I hoar tho same complaints but no attempt to remedy I have worked all the different systems continuously up to the present from sixteen years ago, and am satisfied that to obtain gold from any matrix no system can compete with that which docs so without amalgamation, for gold is only made lighter by mercury pure, and far lighter by mercury impure always presented to the power of the water in the shape of a ball of snow, and this will give an idea how easily gold in this state may be got nd of. lam quite aware of the difficulties that lie in my way to persuade persons having machinery to alter it, and the natural tendency to doubt everything and everybody in mining matters. All I would ask is that you who have two batteries will try one on the following plan, and I have no doubt about how long the other will work in the old way; and if my description fail to cdve the proper idea you, Mr Editor, will be able to give any enquirer information where to see several batteries in operation. For a battery of five heads ■ ( Ist. Scrupulously avoid putting any silver in the box. 2nd. If you have ripples immediately below the box (which I presume most have), let them remain for the present. Keep your float boards as near tojthe silver as it will permit without driving it from the trough. 3rd. Next to your ripples form a trough the length of the ripples four inches wide having four two-inch holes bored oqui-distant in the front board. 4th. For tables a plain board floor with fall lin in 12in, and with a drop of 2in at intervals of three feet for five times at least • the floor to be divided into four equal parts or strips. This will permit of 4 strips of green baize of 20in wide, having a drop of 2in at the end of each piece from top to Dottom. Change your first row of baize jvery hour, 2nd and 3rd every two hours remainder at discretion ; taking care to wash pour baize clean. sth Place your washings into a barrel with a bottle of silver, one handful of soda, and if necessary a pint of strong nitrate of mercury -this last presumes some grease about. Hie barrel should be two-thirds full of dirt jwith sufficient waLer to form a paste, no .more ; revolve 18 hours, then stop and fill itne barrel with water. After revolving for :o hours more, pour out into a trough, at the ,same time allowing the silver only to flow into the shaking table, which must be equally divided in the compartments. If preference bo given, put most in first course. What comes from cleaning out of boxes must be well sifted, and put through the barrel and table in the same way, the remains to be taken back to the hoppers. This completes the brat and general arrangement for saving the bulk of the gold ; it has been tried by analysis and experiment against all the systems known, and is being gradually adopted by all deep ground mining companies,—in fact it must force itself upon us whether we will or not.

But to complete a thorough system such as our reefs really require, it is needful in the bth place to gather the stream from the tables, and carry it to a round buddle (a description of which 1 would gladly give) there to separate all the minerals from the quartz and rubbish. What remains in this buddle should be put through a second time or through a second buddle to ensure its freedom from sand ; thence to be put through a calcining turnace and sufficiently roasted to be treated by either an Arastra or Chilian mill—l prefer the former for manv reasons. We are ed to infer from MrUlrich's report that this latter psocess involves considerable difficulty ■ in my opinion it is equally simple with any of the foregoing processes. The furnace especially may be simply constructed, but equally efficient as the most elaborate, and more so for things on a small scale. The Arastra is a simple piece of machinery and very inexpensive compared to the ponderous Unhan mill, and I am aware where they are m operation side by side doing the same work and equally efficient. This style of amalgamation has several advantages It is not so liable to be affected by grease from the battery, which with all care will find its way into the box. Whatever minerals may be in combination will have no effect on clean go d. The surface of silver in the ripples will always be bright, and may be locked up from Monday morning to Saturday night itw amalgam from washings being cleaned up aaily, not only affords a good idea of the quality of crushing stuff, but leaves no quantity of amalgam about or on copper plates,—a fact in itself sufficient to suggest a change It also saves a quality often half mineral half gold which adds considerably to the returns where otherwise it must bo washed away; the inference of which will lead to the adoption of the second process I have laid down. It is also more simple and cheap for-the erection of batteries, as it will do away in a measure with heavy cumbersome boxes, and expensive made ripple-tables and copper plates. It is also a very great saving in quicksilver, with a certainty of its action ; never getting foul unless by accident. It also ensures a method of obtaining the whole of the gold, or more than any other process at present iii use. In laying this before the public I have done so in plain terms, not to lead persons to suppose I am parading a new thing, or one purely of my own imagination, but"one which I have used for the past ten years, and when I say that 1 have been among quartz crushing since 1858, 1 may be entitled to know which of the many ideas on this subject is nearest to the correct thing.