GOLD MINING
[EIRI/EDPR/4559] J.C.: 2776XL
INTRODUCTION
Gold a bright yellow metal with resplendent luster. It is exceedingly malleable and ductile. It can be beaten into the sheets so thin that 2,50,000 of them may be placed one over another to form a pile one inch in thickness, it can be drawn into wires so thin that a length equal to 50 miles weight just 1 oz. It does not oxidize in air or oxygen at any temp. It is unaffected by the hydrochloric acid, nitric acid and sulphuric acid, even at temp. 100oC. A mixture of hydrochloric acid (Aqua Regia) dissolves the metal. It is not attacked by the alkali hydroxides, sulphur and sulphur dioxide, but is acted upon by the hydrogens, bromine being the most active. It readily amalgamates with mercury, a properly which has been taken advantage of in the extraction of gold from antiferrous sand in which gold is present in a finely dispersed form.
Gold is widely distributed in nature, though in minute quantities. It is present in significant concentrations in source quartz views and alluvial gravels, and these constitute the principal sources for the commercial extraction of the metal. It occurs in sea water in low concentrations (5-269 parts in 100 millions) and its recovery from this source is uneconomical.
Owing to its bright appearance, unalterability in air and occurance in the native condition, gold was probably one of the earliest metals discovered by the man. It is the metal most used even today for jewellery and international monetary transactions.
There is no reliable record of the period when the gold mining was first started in India, but some ancient mines are probably more than a thousand years old and some of them extended to great depths below the surfaces. Ancient working were reinvestigated and mines in Anantpur (Madras), Hutti (Hyderabad) and Kolar gold field (Mysore) appeared promising. Almost the entire quality of the gold now produced in India comes from the Kolar gold field.
Once the ore is mined it can be treated as a whole ore using a dump leaching or heap leaching processes. This is typical of low-grade, oxide deposits. Normally, the ore is crushed and agglomerated prior to heap leaching. High grade ores and ores resistant to cyanide leaching at coarse particle sizes, require further processing in order to recover the gold values. The processing techniques can include grinding, concentration, roasting, and pressure oxidation prior to cyanidation.
COST ESTIMATION
Ore Mininig: 65,000 Tons/Day
Concentrate Production: 325 Ton/Day
Avg. Gold Content in Concentrate: 2 gm/Ton
Land & Building (10 Acres) Rs. 14.13 Cr
Plant & Machinery Rs. 3.68 Cr
Working Capital for 1 Month Rs. 9.96 Cr
Total Capital Investment Rs. 29.78 Cr
Rate of Return 51%
Break Even Point 32%
CONTENTS
INTRODUCTION
TYPES OF GOLD ORE
OCCURENCE
USES & APPLICATIONS
PROPERTIES & CHARACTERISTICS
MINING AND CONCENTRATING
EXTRACTION AND REFINING
AMALGAMATION
CYANIDATION
EXTRACTION FROM REFRACTORY ORES
REFINING
REFINING FROM SCRAP
ASSAYING
THE METAL AND ITS ALLOYS
DETAILS OF ORE MINING
OPEN PIT MINING
UNDERGROUND MINING
PROCESSING
STAGE 1: CRUSHING AND GRINDING
STAGE 2: FLOTATION AND OXIDISATION
STAGE 3: LEACHING AND ADSORPTION
REHABILITATION & CLOSURE
REHABILITATION
CHEMICAL LEACHING AS AN ALTERNATIVE TO MERCURY
MARKET OVERVIEW OF GOLD
GOLD MINING IN ZIMBABWE
LEADING SUB-SECTORS
OPPORTUNITIES
SIGNIFICANCE OF GOLD IN INDIA CULTURE
RELIGIOUS CONNOTATIONS:
FAMILY HEIRLOOM:
GOLDEN GIFTS:
STATUS SYMBOL:
INVESTMENT:
MANUFACTURING PROCESS OF GOLD RECOVERY FROM CONCENTRATE AND WASTE WITHOUT USING MERCURY
REACTION
PROCESS IN DETAILS
PROCESS FLOW DIAGRAM
METHOD OF MINING AND CONCENTRATION
GOLD LIBERATION (CRUSHING AND MILLING)
THE IMPORTANCE OF GRAIN SIZE
IMPROVING CONCENTRATION
MORE SOPHISTICATED DESIGNS CAN AVOID THIS PROBLEM.
THESE ARE CALLED PRIMARY AND SCAVENGER SLUICES.
GENERALLY, CENTRIFUGAL CONCENTRATING REQUIRES:
MAIN STEPS FOR FLOTATION:
MAGNET
DIRECT SMELTING METHOD TO OBTAIN GOLD FROM CONCENTRATES
INFORMATION ABOUT DIRECT SMELTING
EXTRACTION OF GOLD USING CYANIDE
MODEL OF A MERCURY FREE PROCESSING PLANT
DETAILS OF CONCENTRATION METHODS
GRAVITY CONCENTRATION METHODS
PANNING
SLUICING
SHAKING TABLES
VORTEX CONCENTRATORS
CENTRIFUGES
DETAILS OF GOLD RECOVERY METHODS
DIRECT SMELTING
CHEMICAL LEACHING
HEALTH & SAFETY FACTORS
ANALYTICAL METHODS
SPECTROPHOTOMETRIC METHODS
GRAVIMETRIC METHODS
PRINCIPLES OF PLANT LAYOUT
STORAGE LAYOUT:
EQUIPMENT LAYOUT:
SAFETY:
PLANT EXPANSION:
FLOOR SPACE:
UTILITIES SERVICING:
BUILDING:
MATERIAL-HANDLING EQUIPMENT:
RAILROADS AND ROADS:
MAJOR PROVISIONS IN ROAD PLANNING FOR MULTIPURPOSE SERVICE ARE:
PLANT LOCATION FACTORS
PRIMARY FACTORS
1. RAW-MATERIAL SUPPLY:
2. MARKETS:
3. POWER AND FUEL SUPPLY:
4. WATER SUPPLY:
5. CLIMATE:
SPECIFIC FACTORS
6. TRANSPORTATION:
A. AVAILABILITY OF VARIOUS SERVICES AND PROJECTED RATES
7. WASTE DISPOSAL:
8. LABOR:
9. REGULATORY LAWS:
10. TAXES:
11. SITE CHARACTERISTICS:
12. COMMUNITY FACTORS:
13. VULNERABILITY TO WARTIME ATTACK:
14. FLOOD AND FIRE CONTROL:
EXPLANATION OF TERMS USED IN THE PROJECT REPORT
1. DEPRECIATION:
2. FIXED ASSETS:
3. WORKING CAPITAL:
4. BREAK-EVEN POINT:
5. OTHER FIXED EXPENSES:
6. MARGIN MONEY:
7. TOTAL LOAD:
8. LAND AREA/MAN POWER RATIO:
PROJECT IMPLEMENTATION SCHEDULES
INTRODUCTION
PROJECT HANDLING
PROJECT SCHEDULING
PROJECT CONSTRUCTION SCHEDULE
TIME SCHEDULE
SUPPLIERS OF RAW MATERIALS
SUPPLIERS OF PLANT AND MACHINERY
SUPPLIERS OF FILTER PRESS
SUPPLIERS OF SMELTING FURNACE
SUPPLIERS OF GOLD REFINING UNIT
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSETS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)
