Industrial mineral deposit models; descriptive models for three lacustrine deposit types

The third part of three-part assessments is the estimate of some fixed but unknown number of deposits of each type that exist in the delineated tracts. Until the area being considered is thoroughly and extensively drilled, this fixed number of undiscovered deposits, which could be any number including 0, will not be known with certainty. This number of deposits has meaning only in terms of a grade-and-tonnage model. If this requirement did not exist, any wisp of minerals could be considered worthy of estimation, and even in small regions, we would need to estimate millions of “deposits.” For example, it is not difficult to imagine tens of thousands of fist-sized skarn copper “deposits” in parts of western United States—even in this example, we have used “deposit” size to provide important information. In another example, Wilson et al. (1996) estimated five or more epithermal gold vein deposits at the 90 percent level but provided no grade-and-tonnage model, so these estimated deposits could be any size. To provide critical information to decision-makers, the grade-and-tonnage model is key, and the estimated number of deposits that might exist must be from the grade-and-tonnage frequency distributions. In three-part assessments, the parts and estimates are internally consistent in that delineated tracts are consistent with descriptive models, grade-and-tonnage models are consistent with descriptive models and with known deposits in the area, and estimates of number of deposits are consistent with grade-and-tonnage models. Considerable care must be exercised in quantitative resource assessments to prevent the introduction of biased estimates of undiscovered resources. Biases can be introduced into these estimates either by a flawed grade-and-tonnage model or by the lack of consistency of the grade-and-tonnage model with the number-of-deposit estimates. For this reason, consistency of estimates of number of deposits with the grade-and-tonnage models is the most important guideline. Issues about consistency of mineral deposit models are discussed in chapters 3 through 6. Grade-and-tonnage models (chapter 6), which are the first part of three-part assessments, are of particular concern. In this chapter, the focus is on making unbiased estimates of the number of undiscovered deposits.

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Descriptive Models

Quantitative Mineral Resource Assessments ◽

10.1093/oso/9780195399592.003.0006 ◽

2010 ◽

Author(s):

Donald Singer ◽

W. David Menzie

Keyword(s):

Economic Cost ◽

Resource Assessment ◽

Mineral Deposit ◽

Mineral Deposits ◽

Sufficient Information ◽

Cost Models ◽

Policy Makers ◽

Planning Stage ◽

Necessary And Sufficient ◽

Descriptive Models

Mineral deposit models play a central role in an information system that will help the policy makers to make their decisions. Ideally, the different kinds of deposit models would provide the necessary and sufficient information to discriminate (1) possible mineralized environments from barren environments, (2) types of known deposits from each other, and (3) mineral deposits from mineral occurrences. Probably the most important part of creating mineral deposit models is the planning stage in which consideration of the purpose and possible uses of the models should determine the character of the models. The way to describe a model is first by thinking about what it is for, about its function, not the list of items that make up its structure (Churchman, 1968). Although there are many fine compendiums of mineral deposit models (Australian Geological Survey Organisation, 1998; Eckstrand, Sinclair, and Thorpe, 1995; Kirkham et al., 1993; Lefebure and Hoy, 1996; Lefebure and Ray, 1995; Roberts and Sheahan, 1988; Rongfu, 1995; Sheahan and Cherry, 1993), the focus in this book is on deposit models applied to quantitative resource assessment. The focus of this chapter is the descriptive aspects of the deposits because the goal is to provide a basis for interpreting geologic observations rather than to provide interpretations in search of examples (Cox, Barton, and Singer, 1986). Thus, the discussion herein is limited to mineral deposit models specifically designed for quantitative assessments such as those in Cox and Singer (1986), Bliss (1992a), Orris and Bliss (1991, 1992), and Rogers et al. (1995). Mineral deposits modeled for three-part assessments are defined as mineral occurrences of sufficient size and grade that they might, under favorable circumstances, be economic. Although history suggests that we can expect discoveries of as-yet-unrecognized deposit types, the three-part assessments discussed here do not include resources from these deposits simply because they cannot be modeled. Most published quantitative mineral resource assessments that have used models have relied upon descriptive and grade-and-tonnage models (chapter 6), which are also the foundations of other kinds of models such as deposit-density models (chapter 4) and economic cost models (chapter 5).

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TO THE ISSUE OF INDUSTRIAL MINERAL DEPOSIT EVALUATION

ECONOMICS AND INNOVATION MANAGEMENT ◽

10.26730/2587-5574-2020-1-66-74 ◽

2020 ◽

pp. 66-74

Author(s):

Michal Cehlár ◽

Pavol Rybár ◽

Ján Mihók ◽

Jacek Engel

Keyword(s):

Mineral Deposit ◽

Industrial Mineral

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Additional descriptive models of industrial mineral deposits

Open-File Report ◽

10.3133/ofr98505 ◽

1998 ◽

Keyword(s):

Mineral Deposits ◽

Industrial Mineral ◽

Descriptive Models

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Geometallurgical Approach to the Element-to-Mineral Conversion for the Nabbaren Nepheline Syenite Deposit

Minerals ◽

10.3390/min8080325 ◽

2018 ◽

Vol 8 (8) ◽

pp. 325 ◽

Cited By ~ 2

Author(s):

Camilo Mena Silva ◽

Bjørn Sørensen ◽

Kurt Aasly ◽

Steinar Ellefmo

Keyword(s):

Nepheline Syenite ◽

Cost Effective ◽

Mineral Chemistry ◽

Mineral Deposit ◽

Least Square ◽

Fe Content ◽

Cost Effective Technique ◽

Industrial Mineral ◽

Method R

Nabbaren nepheline syenite, a silica-deficient intrusive rock with low Fe content, was the industrial mineral deposit study case in this study. The quality of industrial mineral products are generally based on their bulk chemistry, which are directly related to their modal mineralogy and mineral chemistry; however, these are costly and time-consuming to determine. A geometallurgical-based methodology, known as element-to-mineral conversion (EMC), was applied to estimate its modal mineralogy based on its given bulk and mineral chemistry. EMC is a convenient and cost-effective technique, which can be used to quickly estimate modal mineralogy. Two EMC methodologies were applied: one least square based, LS-XRD, and one regression based, R-XRD. Additionally, average and specific mineral chemistries were used during estimations. The R-XRD method, a method not yet used for EMC purposes, gave better modal mineralogy estimations than LS-XRD. Considering the restrictions in the method, R-XRD shows potential for improvement and implementation at operational scale, making it a valuable geometallurgical tool for increasing resource performance, easing decision-taking processes, and reducing risks. The use of different mineral chemistries did not influence the modal mineralogy estimation, unlike the method used for it.

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