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By Gregg Davidson, Lonnie Jacobs, Brett Zernich, Alan Howard, Robert Pintabona

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of the authors and are not necessarily those of SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2014

By I. Caraconcea, M. Cousineau, S. Gariepy

"Several base metal plants operate in low grade/high tonnage conditions which impose strict cost control on all fronts for their operations to remain profitable. This leads to decisions regarding plant design, procurement, operations and maintenance that often favor cost minimization over value optimization. This may hinder the representativeness of the metal accounting systems while this should be a priority in a low margin environment. Such poor representativeness not only creates confusion in plant scheduling but can also hide suboptimal metallurgical performance. Furthermore, this situation can run undetected for a while since one dominant feature of a poor metal accounting system is its poor self-awareness. During their practice, authors have particularly identified measurement bias and reproducibility, as well as their impact on metal recoveries as areas of concern. These issues have not been extensively reviewed in the specific context of precious metals in base metal plants. Pragmatic solutions are proposed either at the design stage for a new project or to retrofit an actual operation. These solutions should be based on a business analysis that set a value of information matching the contribution of precious metals as well as the potential to use such information to act toward increasing plant profitability. Conclusions are that trade-offs are an inherent part of the design/audit/retrofit of any metal accounting system in any plant processing either base or precious metals. However, compromises must be evaluated on economic/technical ground.INTRODUCTION Every mineral processing plant must produce metal accounting reports (Morrison, 2008) where estimated saleable metal flows and inventories are published. These metal accounting reports are delivered to a variety of stakeholders who use them for internal management purposes (day-to-day plant production planning, plant operation optimization, capital spending, etc.) as well as for external management (royalty settlements, tolling agreements, etc.). Hence, there should be no doubt that state of the art metal accounting is instrumental for mining companies to reach and sustain high-quality corporate governance (Gaylard, Randolph, & Wortley, 2014). However, producing a metal accounting report involves much more than just printing it (Lachance, Leroux, & Gariépy, 2015a). The underlying metal accounting system (Figure 1) is responsible not only for the reliable production of the metal accounting reports but also for the quality of the outcome. As such, the crucial tasks of its design/audit/retrofit should neither be seen as ancillary nor be left as an afterthought."

Jan 1, 2017

By Apostolos Vrakas, Georgios Anagnostou

"INTRODUCTION The small strain assumption routinely made in tunnel analyses remains sufficient from an engineering point of view as long as convergences do not exceed 10%. More specifically, small strain theory assumes that deformations are so small (in relation to the size of the underground opening) that any geometric change in the continuum can be disregarded (Fig. 1a). In fact, however, the geometry is updated during loading (or unloading) according to large strain theory and thus equilibrium and stiffness are evaluated on the deformed configuration of the continuum (Fig. 1b).In problems involving large deformations, where the undeformed and the deformed tunnel geometry differ significantly, small strain theory leads to erroneous and sometimes even nonsensical results (i.e. it can predict wall displacements even greater than the excavated radius under conditions of very low stiffness and strength, high in situ stress and low support pressure). This can easily be verified from the widely applied relationships for the ground response curve. For example, in the ideal case of linearly elastic behaviour, the convergence of an unsupported opening equals (1+?) s0 / E (where E, ? and s0 denote the Young’s modulus, Poisson’s ratio and initial isotropic stress, respectively) and is greater than 100% for E < (1+?) s0. Although convergences are less than 10% in the great majority of tunnelling projects, very large deformations may take place when tunnelling through weak rocks under a high overburden (Fig. 2). This paper will first present a very simple and practicable way to account for large strains, based entirely on the results of routine small strain analyses, and will subsequently show the importance of addressing large strains in tunnel analysis and design with reference to three typical case studies of tunnelling in squeezing ground."

Jan 1, 2016

By M. Cousineau, S. Gariepy

"Current business and corporate environments push for improving metal accounting practices in smelters. The ensuing projects commonly proceed along a bottom-up approach. As such, efforts are first put on reviewing the measurement system and then on remedying the identified weaknesses. The focus is thus moved to mass/metal balance only after the measurements upgrade process has been completed. However, practice has shown that assessing the high variances related to suboptimal measurement processes is complicated without the help of statistical data reconciliation. This bottom-up approach leads to a to-do list that can not only exceed available resources but also lack prioritization in view of achieving the targeted end use. This paper describes an upgrade project done differently where all the three dimensions of the metal accounting system: hardware, software, and people were instead involved at the onset. Personnel was thus trained on data reconciliation software at the beginning of the project to make the reconciled mass balance benefits available earlier in the upgrading project. This has pinpointed the most critical measurements where accuracy and reproducibility should be improved. Overall, not only the instrumentation retrofitting process has been streamlined, but the global risk for the whole upgrading project has been significantly lowered.INTRODUCTION Mining companies are pressured to improve their production accounting practices in response to the strengthening of corporate requirements for timely and accurate production reporting (Gaylard, Randolph, & Wortley, 2014). Smelters are not spared from these changes. However, their unique situation in the mining value chain set them as strategic targets for upgrading projects. They usually have a longer lifespan than concentrators thereby offering an extended lifecycle to justify investments. Furthermore, numerous smelters have toll agreements with third parties. Accurate cost and production accounting is, therefore, a vital piece of information to fix acceptable contract conditions. Mining companies are ultimately aiming at a clearer view of the operating performance of each business unit to improve their business decisions in a competitive environment. This sought for increase in visibility through plant performance can only be achieved through an upgrade of the metal accounting system. Figure 1 shows the different components of a state of the art system (Gaylard, Morrison, Randolph, Wortley, & Beck, 2009)."

Jan 1, 2017

By Paul B. Queneau

Formulation and commercial utilization of solid-waste incinerator slag by-product is the focus of this paper. Particular attention is given to iron aluminosilicate melts having compositions similar to that of nature&apos;s basalt The earth?s crust can be viewed as an environmental laboratory for predicting stability of various silicates; small-scale laboratory experiments are necessary to confirm findings there from. An ideal slag consumes flux additives at acceptable cost, is compatible with furnace refractory, flows readily from the furnace, and has physical properties suitable for its commercial utilization -all within the critical constraint that the slag is environmentally stable. Examples of successful solid waste slagging practice, including tonnage, utilization and pricing, are provided from metallurgical and waste treatment operations of North America. Western Europe and Japan.

Jan 1, 1991

By William M. Knuth

This study involved a review of bonding and bond release practices in the states of the Eastern and Midwestern Coal Provinces. Data was collected from regulatory authorities and site visits to document the bonding and release procedures in the states related to achieving successful reclamation. The regulations related to PL95-87 were reviewed. The analysis included suggested modified or new bond release criteria, a review of applicable bond release inspection techniques was prepared, a conceptual graduated bonding system and incentive procedures for reclamation of surface mine sites to alternative or higher land uses. A number of conclusions and recommendations for further research were included. A detailed bibliography and a glossary are included in the report.

Jan 1, 1978

By CLARENCE G. SMITH

Prior to the actual development of an oil property it is difficult to determine the quantity of oil under the property and the rate at which this oil can be brought to the surface-factors that determine the ultimate value of the property. Consequently, there has been much confusion in devising accounting systems that, during the entire life of a property, will show costs and profits from which the producer can determine whether his property is being worked at a profit or otherwise. The Bureau of Mines publishes this report in recognition of a distinct need for a simple treatise on accounting methods adapted to the peculiarities of the petroleum industry. Probably many companies operating oil wells are not fully acquainted with details important to the welfare of their business, because their account books fail to furnish them with exact and adequate data. With the accountant rests the responsibility of providing the management with reports setting forth the details of the business expressed in fitting terms as well as in dollars and cents. These reports are a means whereby efficiency may be maintained, waste prevented, oil obtained and sold, and money suitably reinvested. They also enable a concern to study the progress of its business in order to conserve to the utmost the possible benefits from an exhaustible deposit of mineral wealth. When managements realize the extent of the waste at their properties more attention will be given to the character of the accountancy records. Herein are presented descriptions and discussions of balance sheets, profit-and-loss statements, and bookkeeping methods peculiarly adapted to the oil business. As far as possible, technical phrases have been omitted in order that those not familiar with accounting terms may be able to follow the subject matter. The systems of keeping books outlined in Chapter X have all been found practical. For brevity as well as clearness the major part of the work refers to the company operating only one property.

Jan 1, 1917

By Donald Leroux, Simon Gariépy, Luc Lachance

"Quantitative information about the quality of metal balance results is often overlooked when making important plant production planning decisions. Not only is this common omission made in a context where many measurements taken in and around mineral processing plants carry significant errors, but it also conflicts with the AMIRA P754 Code of Practice for Metal Accounting. The fact that metal balances are typically published without any indication of data quality may give the wrong impression that the measurements are unquestionably accurate. While it is true that statistical data reconciliation can improve the confidence intervals of redundant variables, there is no data processing technique that brings them down to zero at a finite cost. In this paper, we review the entire data flow, starting from field instruments to metal accounting-based decision-making to show how measurement errors are transmuted into business risks associated with production planning. Necessary conditions for first exposing then quantifying such business risks are stated. Pitfalls to be avoided are also discussed. Finally, a simplified risk assessment and management procedure which considers the quality of metal balance results are applied to a polymetallic mineral processing plant. INTRODUCTION Each and every mineral processing plant has production reporting obligations. In this paper, we are concerned with metal accounting reports (Morrison, 2008) where saleable metal flows and inventories are estimated and published. These metal accounting reports are delivered to a variety of stakeholders who use them for internal management purposes (day-to-day plant production planning, plant operation optimisation, capital spending, etc.) as well as for external management (royalty settlements, tolling agreements, etc.). Hence, there should be no doubt that spotless metal accounting is instrumental to high-quality corporate governance (Gaylard et al., 2014) of mining and metallurgical companies. To this extent, one would have expected industry-endorsed standards to have emerged a long time ago. However, the lack of an accepted set of standard procedures for metallurgical accounting was explicitly recognized as an industry-wide problem only in August 2001 during an SAIMM workshop held in Cape Town, South Africa. Discussions that followed this workshop led to the initiation of the AMIRA Project P754, “Metal Accounting and Reconciliation”, in 2003."

Jan 1, 2015

By Bertrand Wolfman, William E. Stanley

"This paper reviews the traditional mine accounting systems, including ""custodial accounting"" and unit costing, and then suggests that the use of flexible budgets represents a more suitable method of reporting costs in order to assist the mine manager in improving productivity. Examples of various applications are given to show that the result is a clear reporting structure.Custodial Accounting is Emphasized in Traditional SystemsTraditional mine accounting has been mainly concerned with the accuracy of financial reporting to ""head office"" for the use of the directors and the company&apos;s bankers and shareholders. This is often called custodial accounting and it represented the main purpose of accounting when first developed in Europe hundreds of years ago. This important development permitted the establishment of enterprises which were separated from their owners because they could rely on accurate financial reports of management&apos;s stewardship.As custodial accounting is fairly broad and historical in nature, it is often not very useful to the mine manager for ongoing monitoring of performance of mining, milling, maintenance, and other support and staff groups. In spite of the considerable investment in accounting staff and computer support, many accounting systems have not been upgraded so that they accurately reflect workplace performance on a weekly or monthly basis.Budgets are Often FixedMany mines today also still emphasize fixed budgets. Thus, the mine plan which is set in the fall of one year is converted to a monthly tonnage and detailed dollar budget for periods of up to sixteen months in the future. The only certainty in this plan is that actual events will differ; timing, mix of mining methods and production volumes will differ on a monthly basis.Unfortunately, the fixed budget has no capability to reflect these operational changes. It is frozen for the full year. The result is that actual results will inevitably be compared to an outdated target."

Jan 1, 1982

Jan 1, 1991

By Maurice E. Peloubet

This discussion of accounting will describe the statements and the information that the accounting system produces, from the point of view of those who use such systems rather than of those who prepare them and who do the detail and technical accounting work. In any well organized mine, quarry, or other enterprise exploiting a mineral deposit, no matter how small, some clerical and accounting work must be done. Miners and other employes must be paid, supplies must be purchased and issued, and various tax and information returns, which even the smallest enterprise must file, have to be prepared. In this chapter it is assumed that the enterprise has employes of this type and that they understand the fundamentals of record keeping and accounting. It would be impossible here to give sufficiently full explanations to enable a man with no previous clerical and accounting training to set up and operate an accounting and cost system for even the simplest extractive operation. Rather, we shall hope first, to tell the investor and the operator, from the chief engineer or president down to a subforeman, what to expect from the accounting statements and records and how to use this information in his daily work; and second, that it will enable the man with some knowledge of accounting or bookkeeping, but with little or no experience in any extractive industry, to set up and operate a satisfactory system for a mine or other extractive enterprise. For readers who wish to go further, the bibliography at the end of this chapter contains many references. The emphasis has, therefore, been placed on the statements to be produced and the purposes for which they are to be used rather than the underlying books and records. These are, with a few exceptions which will be described later, essentially what might be found in any industrial enterprise and would probably, in the extremely small enterprise, consist of handwritten journals, ledgers, analysis books, payroll books, and stores ledgers. In the larger enterprise, various types of mechanical accounting would be introduced in proportion to the complexity of the operation.

Jan 1, 1959

By John Taylor

?Introduction to Black Mountain ?Historical metal accounting practice ?Metal accounting audit ?Feed measurement ?Sample precision ?Concentrate measurment ?Current metal accounting practice ?Further refinements to the metal accounting practice

Jan 1, 2005

By James E. Chapman

The observations here presented are not those of an expert accountant, but of one who, while he has seen considerable service in the accounting departments of large companies, has spent more time in engineering and operating. This paper is intended to cover, in a measure, mine accounting for small mines, as distinguished from the elaborate systems, requiring many persons in the accounting department. I shall attempt to outline a system embracing the essentials of accounting, and simple enough in form to permit one or two persons to carry it on from month to month, in sufficient detail to be able to tell quickly the grade of ore, the prices received for metals, costs per ton for mining and milling, costs per foot for development, upward or downward tendencies in costs, ore settled or in transit, cash on hand, stocks of supplies on hand, efficiency of labor, etc. As in all accounting, there are two main divisions: that of revenue received for what is sold, and that of disbursements made for what is bought, so in mine accounting we have to consider chiefly the income derived from sales of ore or concentrates, and the expenses incurred in producing the said ore or concentrates in a marketable condition. I. Income The revenue of a mining company from the sale of ore or concentrates comes in the form of remittances, accompanied by settlement sheets made out by the buyer of the mine product, such as a smelting company. It is the duty of the mine accountant (or the person to whom this is assigned in connection with other work) to check these settlement sheets, against both the mine weights and assays, and the schedules of prices arranged between the mine and the smelter. As a rule, quotations for silver, lead, zinc, copper and other metals enter into the settlements, and require checking, as do also bills of lading. Each step of the arithmetical calculation is also checked.

Jan 1, 1917

By D. L. Morrison

The School on the Accounting for Gold, which was organized under the auspices of The South African Institute of Mining and Metallurgy by Dr Hugh E. Bartlet, Consulting Metallurgist of Johannesburg Consolidated Investment Company Limited, was held at the South African Nature Conservation Centre at Delta Park, Johannesburg, on 15th to 17th May, 1989. It was attended by 178 delegates, including 2 from the OK and 4 from Zimbabwe. A total of 19 papers were presented covering the components of gold-accounting procedure, sampling techniques, and new sampling technology.

Jan 1, 1989

By O. Schnake, M. Isakson, C. A. Landolt

The paper presents the conceptual basis for the development of an Activity Based Costing system (ABC) for the analysis and estimation of process costs in mining and metallurgy. In particular, it discusses three major thrusts towards attaining increased efficiency in extraction and processing systems: (a) understanding the link between process and expenses, (b) identifying the chemical and physical factors that govern process costs and ( c) using process and cost models of the production systems. The authors have developed computer techniques to analyze data from conventional accounting and apply them to the development of process based ABC systems. The cost causing activities are linked to management units patterned after the organizational structure of the production system. All costs are associated with specific process functions such as charge preparation, smelting, refining, etc. The level of detail is determined by the quality of data available in conventional accounting systems. The system permits data analysis of historical cases and the projection of costs for new production schemes. Results can be presented in various levels of aggregation, following organizational and/or functional structures. The outputs of the system are tabular and graphical, typically following Pareto analysis concepts.

Jan 1, 2007

By Peter A. Eshun

This paper studies two methods that account for risks associated with gold mining projects such as mineral risks and country risks. The first method is sensitivity analysis, which investigates the effects of a change in any economic parameter such as operating cost, capital investment, gold price or taxes on the viability of the project. The second method is Monte Carlo Simulation technique, which takes into consideration the simultaneous random variation of the economic parameters on the project&apos;s viability. An automated simulation cash flow model has been developed as part of this paper. Sensitivity analysis and the simulation model have been used to investigate the economic viability of the Dokrupe Gold Project (DGP) serving as a test case. It is concluded that, the Monte Carlo Simulation technique gives a more realistic judgement of the economic viability of gold mining projects.

May 1, 2004

By Andy Lemay

Vale (previously known as CVRD) is: ? The second-largest mining company by market capitalization (NYSE:RIO) ? Headquartered in Brazil ? Global workforce of over 100,000 employees including outsourced workers. Vale Inco Limited is a wholly?owned subsidiary of Vale Vale Inco Limited ? is based in Toronto, Ontario Canada: ? Operations and Projects in 20 countries ? Marketing Network extending to 40 countries ? Over 12,000 employees worldwide ? Last years sales of US $8 Billion

May 1, 2008

By A Woodley, A N. Danoucaras

In 2012 the Bureau of Meteorology, under the banner of the Water Accounting Standards Board, released the Australian Water Accounting Standard 1 (AWAS 1). This standard has been in development since 2007 with key milestones being the release of the Preliminary Australian Water Accounting Standard in 2009 and the exposure draft of the Australian Water Accounting Standard in 2010. Throughout this period, the Minerals Council of AustraliaÆs Water Accounting Framework has developed concurrently with the Australian standards and the standards have informed elements of the framework. However, the framework is not identical to the standard as the objectives between the two are different. The objective of the Water Accounting Framework is to create consistency in water reporting of the minerals industry and to assist companies reporting to corporate sustainability initiatives. The objective of AWAS 1 is to provide information to water management bodies to facilitate decisions about the allocation of water resources. Companies are to report on an annual basis - not only physical flows of water but contractual requirements to supply and obtain water - regardless of whether the transaction has been fulfilled in the reporting period. In contrast, the Water Accounting Framework only reports on flows that have physically happened. The paper will provide summary information on aspects of AWAS 1 that are most relevant to the minerals industry, show the alignment and differences between AWAS 1 and the Water Accounting Framework and explain how to obtain the information for the AWAS 1 reporting statements.CITATION:Danoucaras, A N and Woodley, A, 2013. Alignment and differences between the Australian Water Accounting Standard and the Water Accounting Framework for the minerals industry, in Proceedings Water in Mining 2013 , pp 85-90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By E. H. Crabtree, Neil S. Parker

THE custom milling plant of the Eagle-Picher Mining and Smelting Co. is at Sahuarita, Arizona, approximately 20 miles south of Tucson. It is connected by a 2-mile railroad spur to the main line of the Southern Pacific Railroad between Tucson and Nogales. The capacity of the plant is 500 tons per day. The mill is conventional except perhaps in the rather wide variety of ores treated. These vary from straight copper ores, from which only one concentrate is produced, and lead-zinc or copper-zinc ores from which two concentrates are produced, to complex gold-silver-copper-lead-zinc ores, which require the simultaneous production of three or four concentrates. Custom ores are received in lots varying in size from a few truckloads to several carloads. Similar ores, after crushing and sampling, may be commingled, or individual lots may be milled individually. The ores are first dumped either into one of two 200-ton railroad bins, or into one of the two 75-ton truck bins. From these bins the lot of ore is individually crushed in a 24 by 16-in. jaw crusher to 3-in. size, and then to 1/2-in. size in a 3-ft Symons shorthead crusher. After crushing to 1/2-in., the ore is conveyed to the automatic sampling plant. This consists of three Vezin samplers in series, each successively cutting out 10 pct, to pct and 5 pct of its feed. After No. 1 sampler, the material passes through a mixing barrel and is then crushed to 1/4-in. in a set of rolls before passing to No. 2 sampler. Between No. 2 and No. 3 samplers, the ore is again mixed in a mixing barrel. The final sample, consisting of one pound per ton of ore, is taken to the laboratory, where it is further crushed to 1/8-in. in a coffeemill, and then riffled down to the size required for grinding in a pulverizer. The capacity of the crushing and sampling plant is up to too tons per hour, depending upon the character of the ore. After sampling, the ore is stored in five ore-storage bins, consisting of four 200-ton bins and one 175-ton bin. Each of these bins is discharged by means of belt feeders and conveyor to the ball mills, so that ores may be composited for milling in any required ratio, or milled separately by themselves. Fine grinding is done in one 6 by 4-ft Allis-Chalmers ball mill and one 8-ft by 36-in. Hardinge mill. These two mills both discharge to one 54-in. Akins Simplex Highweir classifier. The classifier sands can be returned to either or both mills, so that flexibility in grinding for different ores is easily obtained. Flotation equipment consists of four 66-in. Fagergren machines for copper-lead roughing and six similar machines for zinc roughing. Lead-copper bulk concentrate is cleaned and recleaned in eight No. 18-S Denver machines, and zinc concentrate is cleaned in three 66-in. Fagergrens. Copper-lead differential separation

Jan 1, 1947

By T Harrington, M Cox

There have been many changes in the Australian mining industry during the last 30 years. One of the most dramatic changes, from a geological perspective, is the reduction of in-house geological staffing and an ever increasing reliance on contract and consulting services. As a result, there has been a change in the way geological information is generated, managed and retained within the industry. This paper describes the changes that have taken place in the industry, provides two case studies of how companies manage their geological Intellectual Property and reviews some of the issues associated with management of in-house and outsourced geology services.

Jan 1, 2009