Arthur M Harrisson Ltd

Exploitation of a new limestone deposit for cement manufacture.                                                                                                            Contact

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Limestone is the primary constituent raw material for cement manufacture.  While most limestone deposits areLimestone suitable for cement making, there are some characteristics of limestone which need to be defined in order to establish a usable raw material supply.  These relate to compositional requirements and also the consistency of the deposit in chemical and physical terms.

As well as limestone, other raw materials are required to manufacture cement clinker.  These are commonly  clay or shale, sand and iron oxide.  Not all these are required in all cases, but their availability needs to be known to determine what qualities of cement can be made from the limestone deposit.  In many plants these materials can be made available from the by-products from other industries, such as fly ash from power stations to replace partly or wholly the clay component or waste materials from the steel industry including slags and oxide rich sludges.

crinoidal limestoneApproach

My expertise is in the materials involved in making cement and concrete and the process which achieves this.  The advantage of looking at raw materials in this light at a very early stage is that an assessment of the likelihood of a successful project can be made before expenditure of considerable sums on detailed geological and engineering examinations.

Initially it is necessary to determine the quality of the deposit in terms of chemistry, consistency, geometry,borehole drilling accessibility and influence on the water table.  If there is no available information then a geological survey including a set of broadly spaced boreholes will be necessary.  However, for a deposit to have been considered seriously as a source of cement raw material there will generally have been some previous exploration and it is necessary to access all possible data concerning the potential resource

In this preliminary desk study, in conjunction with publically available or commercial geological data any available borehole data are assessed for:

ghana geol

It is also necessary to discover whether exploitation of the deposit will have an effect on the water table in the location.  This will have a bearing on the ease of extraction, but will also affect the local area and liaison with local authorities will be necessary.

Once the above are satisfactorily established further expertise is required and a quarry plan needs to be established for two purposes.

                1.      The local authorities in most parts of the world will require a five year (or longer) plan of                 how the deposit is to be worked for environmental reasons.

                2.      The quarry manager needs to have a plan of how to operate the quarry in order to                         provide the optimum quality of product to the cement plant over the life of the quarry.                     This is vital in order to prevent exploitation of the easier parts of the quarry in the short                 term then leading to serious problems for the later part of the life of the quarry.

The quarry plans are best managed by means of computer software which collects data both from the initial drilling programme and from the ongoing exploitation of the quarry as further data is made available from exposure of quarry faces and dusts made available from drilling for explosive charges.  This software is widely available commercially, but requires geological expertise to establish and maintain.

A Harrisson 2011