DLKM deserving of recognitionFrom Jim Sinclair's website:
With Commodity Prices Trending Upward, Near-Surface Mine Development and Royalty Model Become Options for Junior Explorers
Posted: May 21 2009 By: David Duval
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"In his book titled, "History of Dakota Territory" George W. Kingsbury describes the development of the Homestake Mine in these words:
“'When the claim was purchased by the Homestake Mining Company the exploration consisted of small surface pits only and some mining men considered its value as doubtful although there were a number of favorable surface indications. The company immediately began the further exploitation of the property and two shafts equipped with hoisting engines were sunk and various drifts were soon under way.
By July, 1878, or the year after the purchase of the claim, the first mill of eighty stamps was constructed and in commission. With the first dropping of stamps it was proved that the mine was a producer and from that small beginning the mine has steadily expanded, breaking all records and setting a new pace in the world of gold mining. Although it is a very low ore, illimitable tonnage is at the disposal of the company and large mills, the most improved mining machinery and great mechanical power enable the mine to pay large dividends.'”
"It’s worth noting that Homestake was listed on the New York Stock Exchange in 1876 and its now dormant South Dakota mine produced approximately 40 million ounces of gold over a 120 year period before the mine’s economic reserves were exhausted in late 2001.
"Mimicking the discovery of other major gold finds at the time, Homestake began as a surface showing with gold values occurring in vein material that was easily distinguishable from adjoining wall rock. Pick and shovel mining provided a bulk sample for metallurgical test work and grade estimation.
"First off, however, the miners recovered gold from alluvial gravels that were eroded from the hard rock vein material. Exploration shafts were then sunk to evaluate the vein material at depth, producing gold in the process to offset exploration costs.
"In many parts of the world (including Africa and Latin America) artisanal miners have already gained access to sub-surface vein material by hand sinking small shafts and mining along the vein structures. In fact, you would be hard pressed to find a major mine in Africa that didn’t have such workings within its property boundaries. These old workings facilitate target selection and the development of a resource base for production purposes.
"Because of its high specific gravity (gold’s relative weight to that of water) gold concentrates in stream beds within alluvial gravels and it can be extracted by mechanical methods that take advantage of the fact it is 19.3 times as heavy as water.
"Gold occurs in many different geologic settings but two basic types of occurrences or deposits are recognized: primary and secondary. Both rely on similar chemical and physical processes to produce economic concentrations of gold ore.
"The Homestake discovery didn’t have the advantage of present day drilling technology to confirm the existence of an orebody whose life would extend for more than 100 years. Instead, the economic viability of the mine was established by mining and processing the easily extractable surface material with equipment that used gold’s specific gravity to produce a saleable concentrate. In the late 1890s, cyanide was employed to recover fine gold from rocks and is still used under carefully controlled conditions.
"Even today, gravity separation is the best proven and accepted technique of concentrating minerals due to its high efficiency and low cost. In addition to gold, gravity separation remains a primary means of concentrating iron, tungsten, tin and coal ores.
"Process plants (mills) for gold need not be large and in fact they are often manufactured and assembled in large industrial centers where skilled trades people are readily available. By employing modular construction techniques, equipment can be brought into a mine site by truck, air transport and in the case of tidewater locations, by sea barge. The various modular sections are simply joined together like a kid’s Lego set on the mine site. As the operation expands, new modules can be shipped to the site and added to the existing plant facility.
"In order to reduce capital requirements, companies often employ contractors to mine their mineral deposits at a fixed price, locking in costs for the term of the contract. With contract mining, a company need not acquire in-house mining expertise or equipment that would only be utilized on a seasonal basis in any event. For smaller operations, contractors can provide services for a sufficient length of time to develop a stockpile for year round milling operations."
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"Physical gold output – even on a small scale basis – provides price leverage to companies in the marketplace, especially for situations where the exploration potential leaves room for future production growth."
more:
https://jsmineset.com/