Guide to the user

This technical handbook on small-scale mining in developing countries serves as a general source of information and as a planning and consulting guide for mining, exploration and beneficiation engineers as well as other technical-staff members of planning and consulting companies and organizations both in developing and in developed countries. Although the handbook caters to the special needs of small-scale mining in Latin American countries, incorporating particularly the traditional techniques employed in countries in the Andean region, it has a worldwide application. Included in this handbook are also guidelines for craftsmen and artisans and their affiliated consulting organizations who are interested in diversifying their product line.

Prerequisites for the successful application of this handbook include a technical knowledge on the part of the reader, as well as the ability to think abstractly and the capability to understand and interpret technical sketches and drawings.

Due to the large quantity of information which has emerged from the complex array of mining activities, a structuring of the data is crucial to ensure the convenient use of the handbook. The handbook covers all basic information about mining, in particular focusing on the extraction and beneficiation of ores, precious metals, coal, salt, industrial minerals, and precious stones. Since the selection of mining and processing equipment relies more upon specific operational data, such as production rate and the degree of mechanization, rather than the type of mineral being extracted, the information given in this handbook is divided into five main chapters according to the following five categories: Analysis, Underground Mining, Surface Mining, Beneficiation and Energy.

Each of these five chapters includes an introduction containing definitions, problem areas, environmental and health risks, and organizational advice. This is followed by a presentation of technical information on individual techniques and procedures, which in some cases is divided into specific work categories. Each of these techniques is summarized in a technical outline containing a compact presentation of the technical data, costs, and conditions and restrictions of application. Especially with regard to the conditions for application, the evaluation of these techniques is based on more subjective criteria; for example, service and maintenance costs can only be approximated in a small-scale mining handbook through comparison with costs for equipment which perform comparable functions. As a result, these evaluations cannot be universally correlated with each other.

The degree of environmental impact is presented on a linear scale, providing an initial basis for defining the technology's effect on the environment. Negative environmental effects through the depletion of mineral resources, or those associated with the supplying of energy, were not taken into consideration here; these effects are discussed in the chapter on Energy. Those techniques that are energy intensive and cannot utilize regenerative sources of energy are included in the environmental impact evaluation. Damage to the environment caused by the manufacture of spare parts for mining equipment are not considered here unless the production pertains to major machinery components. The environmental material-balance sheet for reagents has, however, been incorporated into the data analysis for the most part.

The section on suitability for local production examines the possibilities for manufacturing at the local level. The investigation does not focus on manufacturing by the mines directly, but rather production in non-mining industries such as wood, metal and other special machine-manufacturing shops which, due to the fact that they do not belong to the mining sector, are not equipped with special machines or special knowledge in the manufacture of such mining equipment. Besides providing information on the local conditions required for machine manufacturers, the handbook also includes photos, drawings and simple dimensioning aids. Every technical outline has a numbered title and name of the technique or technology, mining sector and work category, enabling rapid identification and classification of the technique or technology according to its area of application.

The technical section of the handbook also includes names of manufacturers and bibliography for further information. Abbreviations used in the handbook are explained in the List of Abbreviations.

A Subject Index is provided at the end of the handbook to assist the reader in quickly locating particular text subjects within the work-organization and technical sections.

Those mineral resources which require special mining or processing techniques are presented in the handbook separately:

- industrial minerals extraction in the chapter on Surface Mining, since this primarily involves the mining of bulk materials. The techniques presented in Chapter D are suitable for the processing of raw materials for industrial and construction purposes, and can normally be used without difficulty.

- techniques for diamond processing are presented in Chapter D, whereby sorting of raw materials is the main difficulty since in some cases the feed material contains significantly less than 1 g/ton valuable mineral.

- gold beneficiation is also contained in the section on beneficiation and processing. This additionally includes information concerning the problems and risks of contamination in the amalgamation process as well as a collection of flowsheets from various gold-processing plants. Special separation techniques for gold extraction are described in Subchapter 15. Crushing, classification and some sorting processes employed in gold beneficiation are not gold-specific techniques and are therefore found in a beneficiation of the handbook. The mining of gold, whether surface or underground, likewise does not need to be addressed separately.

Some of the described modern techniques for smallscale mining are under patent protection in case of local production. The valid legal requirements must be considered.