Mining & Mineral Resources

Mining & Mineral Resources 2016-11-29T13:10:39+00:00

Heap-Leaching for Gold ProductionMineral Exploration

Mineral exploration projects and environmental investigations have many common characteristics. Both require a familiarity with the geologic literature and both involve drilling, sampling, and laboratory analyses for anomalous compounds. Mineral exploration involves the search and evaluation of significant concentrations of economic metals and other elements found in naturally occurring deposits at or near the surface of the earth. Mining involves the removal of overburden and ore-grade materials to generate economic benefit. Mining of some minerals is also conducted via in-situ methods by the uranium industry, generally called solution mining (Campbell, et al., 2009, pp. 42-51). It is an environmentally friendly method of mineral extraction and can scientifically reduce production costs relative to those involved in surface and underground mining of the past.

Value is created by mining a mineral commodity for use by society in making a product of value to society. For example, gold has an intrinsic value as is, but uranium needs to be chemically combined into “yellowcake” which is then enriched to make pellets for use in nuclear power reactor cores. Successful mining projects consist of multidisciplinary activities, such as in heap leaching of precious metals, for example, and require a careful blend and balance of geological, chemical, geotechnical, engineering, financial, environmental and managerial expertise (Campbell, et al., 2007).

Natural Resource Development

Here are some reflections from within the Natural Resources Group on the history of exploration in the U.S. by Ruffin I. Rackley, I2M Associates’ Senior Associate (Emeritus):

“Gold is where you find it” was the guide to prospecting prior to 1950 and the prospector used gold as a guide in locating mineral deposits that were partially eroded. Back then the prospector, usually alone with a jackass to carry his meager belongings, panned for gold in streams and knocked on outcrops until he found some valuable minerals, if at all. He probably let out a yell, staked his claim and recorded it in the local courthouse or mining district office, and started digging. Today, the professional exploration geologist, armed with two or three academic degrees, has to approach things differently because those exposed mineral occurrences of economic interest have likely all been found. Geologists have to work through hundreds to thousands of feet of cover using every geological, hydrochemical, geochemical, and geophysical method available to assist in the search.

Today, finding an ore deposit requires an indirect approach. All earth resources, even some common varieties, such as sand and gravel, require some form of concentration process to make a commercial mineral deposit because the natural abundance of the sought-after element in the earth’s crust is normally much too low to be an economic deposit. Fortunately, most of the mineral commodities, including uranium, precious and base metals, have a natural concentration process in the Earth that provides a much broader target for exploration than the mineral deposit itself. These processes leave evidence of their presence over an area a few times to a few hundred times the size of the mineral deposits themselves. That is why such activities as geochemical surveys, geophysical surveys, and drilling, are conducted. With some luck, this allows the exploration team to sometimes locate the actual mineralization much more efficiently in both time and money than every before.

Finding some evidence of gold or other mineralization is only the beginning. The geologist must then determine by drilling and sampling if there exists sufficient grade and tonnage to make a mine under the anticipated economic conditions. (One of the senior principals of I2M published a well-known text on drilling (more)). If the determination is made, it is only then that the mineralization found becomes “ore”; but should the market price fall below a certain level, the ore is no longer economic to mine and process.Exploratory drilling on possible gold mine in Nevada, USAThere are big risks in mineral exploration, but big rewards if exploration is successful in finding and defining an economic orebody. There are big mining companies and so-called junior mining companies, the former look for world-class deposits of high value and high cost to produce (such as the Pebble discovery in Alaska), while the latter attempt to make profit from smaller deposits. Some of the latter also have discovered world-class deposits in the past (such as those exploring in the Athabaska Basin in Canada), but these are usually bought-out by the large companies (often retaining royalties) because only they can handle the large scale, high costs, and long payout involved in developing the large deposits.

I2M Associates has an outstanding team who are already knowledgeable in the prospective uranium, gold and silver, base metal areas around the United States and overseas, and who are ready and able to manage substantial programs to acquire known mineralization with a combination of classic techniques we and others developed in the 1960s and 70s and of those available today. Then, once significant mineralization has been found, we would further define the horizontal and lateral extent of the economic portions of the mineralization and then make recommendations for the next phase of the project for a client that often involves sale of the property, a merger or additional acquisitions (more).”

Environmental Protection

In general, mining and mineral resources are also directly linked to the environmental field, hence our mantra “Natural Resources Development with Environmental Protection.” The former is the first stage of supplying society with its building blocks while the latter is the last stage of cleaning up after society’s needs have been met. As society learns to mine its needed raw materials in more environmentally sound ways, so too will society learn to produce the products it needs in more environmentally friendly ways by improving handling and storage techniques and by reducing waste. In the process of making a product, wastes are produced and which have occasionally been improperly handled and expediently disposed of at locations that often threatened the health and well being of humans and the environment. Now, environmental investigations search for and evaluate the residual concentrations of anthropogenic waste or by-products such as metals, hydrocarbons, solvents, pesticides, herbicides, and other industrial waste constituents found in and around industrial centers in concentrations considered, in many cases, to be potentially dangerous to human health and the environment, i.e., to other fauna, flora and other natural resources. I2M is fully cognizant of the need for both natural resource development and environmental protection.

In Situ Mining of Uranium

The mining and mineral resources disciplines involve a number of activities, ranging from developing or reviewing mineral exploration programs for potential financial investors through developing mining plans to environmental permitting. When disagreements arise in such projects they usually are because some aspect of the project has failed. This may be a result of an ambiguous agreement between two parties, agreed to originally for the sake of project expediency. Now, each claim is based on their interpretation of the original agreement. Often, an investigation conducted to underwrite the project is later found to be allegedly flawed and a partner wishes to withdraw from the project, without financial malice or obligation. But litigation can result as a common course of business to rectify some misdeed or other perceived wrongdoing.


Litigation will continue to thrive on projects where expectations are not based on reality, but on an interpretation of apparent reality. The highly subjective and speculative nature of many investigations which support mining-project development are part of the risk of the undertaking, but prudent, independent investigations, conducted by appropriately trained, experienced personnel holding the appropriate professional geological certifications and state licenses are required to minimize potential loss, not to eliminate it. The distinction between the two forms the basis for much litigation. Other forms involve economic analysis of the ore reserves, and range from the projected cash-flow to environmental permits of a proposed or existing mining project, to mine dewatering, water-supply development, and mine environmental impact statements prepared for state and federal regulatory approval.The costs to pursue such, however, are large with outcomes uncertain. For additional information, see Litigation Support (more).

Below are a few case histories of particular note over the years:

Tasmania, Australia, Large Tailings Lake Contains Significant Gold and Silver: I2M provided independent assessment of mine tailings from a large base- and precious metal mine to remediate some 10 million tonnes of waste after zinc and lead were removed by multi-stage processing. The waste consists of 70% sulfide minerals (of pyrite, arsenopyrite, sphalerite galena, chalcopyrite, and tetrahedrite), all of which would oxidize to form acidic mine drainage if allowed to sit in piles open to the atmosphere and oxidizing rainfall. To minimize oxidation, waste is currently being stored below a large engineered lake. Subsequent analysis by I2M personnel of sampling laboratory results showed that significant concentrations of gold and silver are available within the minerals in the submerged waste tailings. I2M made recommendations based economic modeling for removal and transportation with offsite recovery of the precious metal. After the waste tailings are removed offsite, and lake-water chemistry adjusted, the lake could be drained and the water released to the original stream without environment damage returning the area for multiple use. By physically removing the tailings by dredging while covered by the lake water, this eliminates potential damage from potential acid mine drainage and potential release of iron sulfate, arsenic and lead to an especially sensitive wildlife area of central Tasmania, Australia.

Vietnam, Đồi Bù District, Hòa Bình Region SW of Hanoi – Independent Evaluation of Gold and Silver Mines and Processing Plant: I2M conducted onsite independent investigations of small operational gold and silver mines consisting of sampling ore working face via adits extending some 2,500 feet for the purpose of determining if the ore deposits being produced in the two mines visited could support expanded production. And, if the sulfide processing plant, located some 25 miles down from the mine and adjacent to a valley, was operational. The processing plant consisted of the primary of crusher, floatation, and cyanide recovery, and final filtration recovery. I2M determined that the tailing pond that received waste from the final filtration circuit had been breached, emptying into an adjacent stream (dry season). Both tailing sediments and stream sediments were sampled and the sediments were found to contain very high arsenic, lead, and cadmium. I2M personnel recommended that a comprehensive follow-up investigation be conducted by the local government for taking samples of the stream water (when not dry), associated sediments downstream, adjacent shallow rural water wells and in the area where the subject stream enters the rice paddies in the valley below for the purpose of assessing environmental concerns.

Eureka County, Nevada – Open-Pit Mining and Gold-Silver Heap Leach Recovery: I2M personnel purchased a mining property from a major mining company (Amselco) for a consortium of Norwegian-Italian-Swiss investor groups. and served as mine management. After conducting extensive drilling and coring, designed mine plan, designed and constructed 9-mile haul road from mine to pads, the decision was made by the consortium to initiate mining. The new leaky-pipe cyanide leach system, and existing electrolytic recovery and smelting systems to recover precious metal dore were upgraded. I2M personnel managed day-to-day mining, heap-leaching operations, provided oversight of dore production and senior I2M personnel transported dore to refinery in Salt Lake City, Utah. I2M also conducted environmental monitoring of groundwater in plant area, and initiated and implemented a comprehensive safety program. I2M personnel also provided liaison with state and federal regulatory agencies.


Queensland, Australia – Magnetite Mine Development License Application Preparation: I2M Associates, LLC was selected by an Australian mining company to prepare an MDL application to be submitted to the Queensland government in preparation for mining. I2M personnel were relocated to Townsville, Qld. to coordinate and assemble the permit application. The process required 8 months in-country meeting with governmental regulatory agencies, researching requirements, and assembling geological, environmental, and mining data for assessment and description.


Brooks County, Texas – In-Situ Uranium Solution Mining and Processing: I2M Associates, LL was engaged to conduct a comprehensive independent evaluation of the uranium production system in operation for the purpose of preparing a NI 43-101 report for the client and the Vancouver Stock Exchange and other exchanges. This investigation included a review of the uranium resource drilling and logging data used by mining company to characterize the uranium roll-front orebodies in the primary and secondary zones, and of the consumption rates by processing plant chemical systems, wastewater injection well condition and history, combined with a review of state and federal permits Associates, LLC Environmental, Inc. and associated filings and reports. Conducted comprehensive economic modeling of ore grade, market price, and multi-case sensitivity to potential changes in project-price conditions.


Wayne County, Utah – Coal Mine and Loading Facility (Green River, Utah): I2M personnel conducted independent assessment in due diligence for funding agencies of the subbituminous coal resources present in the shallow subsurface amenable for open-pit mining involving drilling, coring, geophysical logging, mapping of faulted coal beds. Completed calculations of pit-recoverable reserves available for transportation 70 miles by road to a new 25,000 ton stockpile for transferring at a railroad facility with automatic loading for transportation to coal-fired power plants near Las Vegas. I2M personnel determined that coal reserves were approximately 25% of that estimated by project consultants and approved by associated banks funding the fast-tracked project.

Monroe County, Louisiana – Investigation to Address Lignite Beds Disruption During Mining Resulting from Excess Pore Pressure: I2M personnel were engaged to conduct a comprehensive groundwater flow-net analysis of the future mining blocks to determine areas of excess pore pressure causing lignite bed movement as overburden was removed in advance of bucket-wheel mining of lignite. This activity was conducted for the purpose of minimizing mining of underclay that would decrease lignite quality by increasing “ash” levels to the coal stream sent by conveyor to the mine-mouth power plant nearby. 250 groundwater monitoring wells were drilled and installed with designed screen lengths, and logged (both to record lithology and by geophysical logging of gamma, SP and resistivity). Top of well casings were surveyed for elevations and “slab” section flow net maps and surface elevation maps of anomalous areas were constructed and keyed to master mining maps for future reference by the operator. Results identified mining areas of high-, medium-, and low-pore pressure that were directly related to permeability differences present within the underclay and its thickness. Small-diameter pore-pressure relief wells were installed throughout the areas mapped as exhibiting high-pore pressure. Within 6 months, the local monitoring of pore-pressure (water levels) in wells indicated a marked decrease in pore pressure. Three years later, mine management indicated to I2M that the lignite-bed movement after removal of overburden had be reduced to near stability, as planned, and that they were moving high-quality lignite to the power plant by conveyor now after passing the anomalous subsurface areas of the mine.

To review the technical news on selected projects and some of the technologies and techniques involved, search “mining” “Gold”, “Uranium” or related key words in the I2M Web Portal (here).

Feel free to contact us to discuss your project needs or to arrange a speaking engagement by one of our Associates for a professional training session, a technical conference, society meeting, or for a graduation ceremony or other function where the knowledge and experience of our Associates may be of interest to your group.

The I2M Principal responsible for this discipline’s activities is:

Michael D. Campbell, P.G., P.H.

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I2M Associates, LLC offers experienced engineers, geologists, hydrogeologists, and other scientists with many years in environmental assessments, including remediation management, mineral exploration and mining, project management, and mergers and acquisitions. Related areas of expertise include forensic and feasibility studies in the environmental and mining industries, and environmental site assessments, due diligence assessments, and impact assessments in addition to brownfield redevelopment and management (as well as grant application assistance) in the U.S, and for state and the U.S. governments, and the legal community around the U.S.

Case Histories

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