Top

Laboratory


Activities Present And Future Prespective Services

Analysis of mineral samples forms a vital step in the value chain of mineral development. Samples received after prospecting and exploration by department, public sector undertakings, and private entrepreneurs ars analysed in the Petrography and Chemical Laboratory of this Department to establish the physio-chemical cherecterisation of the minerals.

The petrography and Chemical Laboratory has been providing the services to the mining and mineral community for a long time. However, in order to broad-base the activities and services rendered by the laboratory and popularize them, it has been felt since long to bring out a brochure so that mining and mineral community and public at large can take advantage of them for more and better development to the mineral sector.

In order to bring out Petrography and Mineral Chemistry Laboratory of this department to the fore front, and to give a new impetus to mineral development, we have initiated action to strengthen and upgrade the laboratory and to provide a lead in starting R & D which was visualized in early in 1979. We Wise to thank our colleague, Shri J.V. Bhatt, Additonal Director (Development ), Shri A.C. Shukla (Sr. Geologist ), Smt. R.B. Pandya (Analytical chemist ) and staff for having worked out its contents and sitting long hours with me to bring out refinements of the same.

I would also like to acknowledge the encouragement given to us by Shri C.K. Koshy, Additional Chief Secretary, Industries and Mines, Gandhinagar. The support given by Dr. V.V. Ramma Subba Rao, Managing Director, Gujarat Mineral Department Corporation needs a special mention for not only bringing out this brochure but also for providing various instruments and infrastructure to the laboratory.

We hope that this initiative will go a long way in fulfilling the needs and expectations of the mining and mineral community and public at large.


INTRODUCTION

Gujarat is endowed with various industrial minerals such as Agate, Limestone, Lignite, Calcite, Fluorite, Bauxite, Dolomite, Bentonite, china clay etc. Commissioner of Geology and Mining is engaged in the exploration of minerals. Samples collected during prospecting are analyzed, identified and categorized for its industrial applications.

Department of Geology and Mining started its Laboratory Wing during 1964-65 with limited facilities for analysis. With the expansion of exploration activities and establishment of mineral based plants, Laboratory has acquired modern equipments for analytical work. Expansion and strengthening of different wings were done with the co-operation and help from Gujarat Mineral Development Corporation.

The Petrography and Mineral Chemistry Laboratory is equipped with modern mineral testing equipments like X-ray Diffractometer, Atomic Absorption Spectrophotometer, Differential Thermal Analyser-cum-Thermal Gravimetric Analyzer, Infra Red spectrophotometer, Particle Size Analyzer, Sedimentation Balance, modern Microscope with Photo micrographic attachment etc.

It has the distinction of being recognized as Research and Development Laboratory for mineral, Vide Government Resolution No. MCR/2179(145)2597-CHH dt. 20.3.1979. Scientists and analytical staff are well-trained in reputed National and Regional Research Laboratories. It provides services to the minerals and mining community and mineral based industries for mineral analysis.

OBJECTIVES

  1. To assess quality of Ores, Minerals by Chemical, Physical testing Instrumental analysis.
  2. To study the minerals with respect to industrial applications.
  3. To study polishing characters of the decorative stones and testing engineering characteristics.
  4. To provide analytical services to corporations and public entrepreneurs on "No Profit no loss Basis".
  5. To identify the mineral and associated impurities with the help of modern instruments.
  6. To determine specific gravity of rocks and minerals.
  7. To apply Remote Sensing techniques for regional stratigraphy and structural continuity of Rock types.

AREAS OF ACTIVITIES

There are three wings in the Laboratory which carries out mineral analytical work,rock identification and establishment of Lithology. All the three wings perform physio chemical study of rocks, minerals and clays and quick appraisal of geological set-up.

PETROGRAPHY :

Megascopic examination of samples are carried out for its color, grain size, textures, structure, reaction with certain chemicals etc. and to identify the rocks and minerals. Optical properties under polarizing microscope are examined to identify the mineral assemblages in rocks.

MINRAL CHEMISTRY :

Mineral chemical analysis is carried out by volumetric, gravimetric and colorimetric procedures as per ISI methods. By above methods, existence of different radicals and their percentage are determined. Physio-chemical characterization study of minerals and clays are carried out for its industrial applications.

REMOTE SENSING :

With the help of satellite imagery and aerial Photographs, comprehensive geological maps are prepared indicating regional stratigraphic and structural continuity of rock types. It associates itself in the technological advancement by taking up collaborative projects with Indian Space Research Organization (I.S.R.O.) Ahmedabad, Regional Remote Sensing Service Centre (R.R.S.S.), Bangalore and Indian Institute of Technology (IIT), Mumbai etc. for speedy identification of Lithology.

PRESENT STATUS AND FUTURE PERSPECTIVE :

Laboratory carries out mineral analytical work, identification of rock, engineering characteristic of Decorative and Dimension stone, geological, structural, stratigraphical.

It is planned to expand the activities of Petrography Wing by introducing geotechnical and coal petrography divisions. Expansion of fuel testing wing for ultimate analysis of Lignite is under way. Clay testing wing will be strengthened by providing. “Mozely Hydrocyclone Assembly Test Kit” for Particle Size Separation Study of China clay.

Research and Development projects for benefication, upgradation of low grade minerals and mineral waste will be taken up in collaboratin with INDEXTb, G.M.D.C. and Other Research institutions in the field.

It is also intended to upgrade the facilities and technical capability keeping liaison with advanced laboratories and training institutions.

SERVICES PROVIDED BY THE LABORATORY

A. PETROLOGY LABORATORY

POLARISING MICROSCOPE:

It acts on the principle of polarized polychromatic light and its interaction with minerals. Provision of studying minerals and rocks under both reflected and refracted light helps us to decipher relationships between silicates (generally transparent/translucent) and ores (opaque) which is necessary for understanding constituents of the rocks and minerals. An inbuilt photomicrographic camera is attached with the microscope for documentation of texture and structure constituents of the sample.

THIN SECTION STUDY OF ROCKS AND MINERALS :

Megascopic examinations of samples are carried out for its color, grain size, structure reaction with certain chemicals etc. to identify the rock and minerals.

MODEL ANALYSIS :

Optical properties under polarsing microscope are examined to identify mineral assemblages in rocks based on various optical properties of minerals and mixture. Texture, alteration etc. are also observed and based on totality of characters identified, a suitable nomenclature is given to the rock.

To know percentage of various minerals in the rocks “Elco’ automatic point counter” is attached to a polarising microscope.

An automatic sophisticated camera is also attached to polarising microscope to take picture of the thin section for the purpose of illustration.

SPECIFIC GRAVITY :

The specific gravity of the rock is determined to make use in calculation of carrying out reserves of particular rocks/ore/minerals in specified area.

CUTTING AND POLISHING CHARACTERS :

Decorative & Dimension stones geotechnical characters are determined. For the knowledge of polishing property, Kerosene driven “Jallor made” cutting and polishing machine with “1’ x 1.5’ x 1.5’ blocks size is erected.

COMPRESSIVE STRENGTH :

This property is also carried out in Laboratory to find out its strength under various weights so as to make use of it for various constructions including Engineering construction.

B. MINERAL CHEMISTRY LABORATORY

INSTRUMENTAL ANALYSIS :

Laboratory is carrying out mineralogical analysis and physical characterisation for the identification of rocks and minerals by using various instruments e.g. as X-ray Diffractometer, Atomic Absorption Spectrophotometer, Differential Thermal Analyser cum Thermal Gravimetric Analyser, Infra Red Spectrophotometer, Master Size Particle Size Analyser etc.

MALVERN PARTICLE SIZE ANALYSER

Malvern particle Size Analyser :

The Malvern particle size analyser is working on the principle of Laser. It is a recent rapid method for determination of particle size. The importance of particle size distribution in commercial applications like setting time of cement, efficiency of heterogeneous chemicals catalysts like Fluorite, printing quality of inks, shrinkage and solidification of clays, caking properties of coking coal, additive property in lubricating oil and glass hardness in paints, grinding and milling of ores and abrasives, insecticides etc. Knowledge of size distribution is important for controlling product effectiveness, controlling cost, conserving energy, minimising pollution and preventing health hazards.

SEDIMENTATION BALANCE

Sedimentation Balance :

: The Balance is working on gravity velocity and Strokes Law equation. This instrument is used for particle size analysis with a consideration of shape and size. The settling behavior of a particle suspended in a fluid is widely used for particle size determination. It will give information regarding application of the clays and minerals powders.

BOMB CALORIMETER

Bomb Calorimeter :

The instrument is used for determining calorific value for fuel material. In the instrument, fuel material is taken in a crucible and oxygen is filled up. Afterwards, it is fired with the help of electric current. Due to burning of fuel material, heat is generated and it gets spread in the water surrounding the bomb. The increase of temperature of water is measured with the help of thermometer.

GENERAL CHEMICAL ANALYSIS :

In the Chemical analysis Unit, we undertake chemical analysis of Minerals and determinations of individual constituents such as SiO2, R2O3, Al2O3, Fe2O3, TiO2, CaO, MgO,SO3,P2O5,MnO,Na2O, K2O and LOSS on Ignition etc.

In the chemical unit, we always use high grade (AR Grade) chemicals for determination of constituents. Analysis is carried out as per ISI Specification procedures.

PHYSIO-CHEMICAL ANALYSIS :

In Clays, determination of physical properties is more important. Following facilities are available in the Laboratory.

a. Recovery : Recovery by means of washing is carried out in laboratory scale pilot levigation plant.

b. In China clay, fire clay and plastic clay color and visual examinations, slaking nature, plasticity by hand feel and by Atterberg’s number. Water of plasticity, Whiteness, Dry linear shrinkage, Base Exchange capacity and Fired properties at different temperatures from 900° C to 1400° C are carried out.

c. Wet and Dry sieve analysis with the help of mechanical sieve shaker.

d. In Bentonite, Gel value, Swelling power, Liquid limit, Filter loss, Specific Gravity, pH, Base Exchange capacity, Viscosity, Oil absorption, Exchangeable calcium ions and Grit content are determined.

FUEL ANALYSIS :

1. Proximate Analysis :

It includes determination of Moisture, Ash, Volatile Matter, Calorific Value and Fix Carbon by difference.

2. Different forms of Sulphur :

Different forms of Sulphur: It includes Total Sulphur, Sulphate Sulphur, Pyretic Sulphur and Organic Sulphur by difference.

3. Ash analysis :

Chemical analysis of Ash.