gold mining (ore mining of 65000 tons/day with concentrate production of 325 tons/day)

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)