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Showing posts with label METALLURGY. Show all posts
Showing posts with label METALLURGY. Show all posts

23 Mar 2013

Gravity Stamp



Gravity Stamp
Some crushers specially designed for specific ores or materials can lie installed and operated economically for that particular material. Most of these special crusher have been employed in the past and new very few industries make use of these, since the requirements have been met by making changes in designs of universal machines. Among this category the most commonly employed in the past in the gravity stamp used in gold are making whereas some others such as Bradford beaker, disk crushers, etc have been used for soft materials.
Some of these machines can be used for coarse crushing, whereas some can be employed for fine crushing.
Gravity stamp mills are one of the oldest methods for size reduction in the intermediate and fine size ranges, loath are obsolete now. The stamp is an impact crusher and operates on the principle of mortar and pestle. Gravity stamp mill consists of the mortar box on a concrete block in which crushing is accompanied by 5 (or 10 ) stamps ( beary blocks).
The stamps are raised by can operating under collars fastened to the upper past of the shaft and drop by their own weight on a hard metal slab. The ore is introduced continuously in the mortar, which falls on the block. The crushing operation is carried out in aqueous pulp. Its reduction ratio is quite high upto 150 ( 8 am piece can be reduced to 0.05 am) and thus in the past stamp mills have done a great service in crushing of gold ores for amalgamation. 

PAKISTAN’S MINERAL RESOURCES


PAKISTAN’S MINERAL RESOURCES



Mineral Development Department:

This department was created in Sindh in 2001 in pursuance of the National Mineral Policy, 1995. The department has taken all necessary steps for further establishing its field office. The province of Sindh has large quantities of minerals. In all there are 24 minerals which are being mined at present. The province also has large quantities of coal and granite reserves. The granite area which was previously inaccessible has now been connected with Karachi by network of roads and other facilities like Rest House etc. It is also proposed that Granite Park should be established at Nagarparkar. Karunjhar Range of Mountains in Nagarparkar has huge reserves of granite and other rock types of extractable thickness which has the potential to compete the international market.


Mining and Quarrying:

Pakistan has a widely geological frame work, ranging from pre-Cambrian to the present that includes a number of zones hosting several metallic minerals, industrial minerals, precious and semi-precious stones. Although many effort have been made in developing geological products, institutional, academic and Research and Development infrastructure, much remains to be done to enable this sector to take full advantage of its endowment. As a result of various efforts devoted for the development of mineral sector, resources of several minerals have been discovered over the last many decades, including world class resources of lignite coal deposits at Thar, Sindh, porphyry copper-gold deposits in Chagai, Balochistan, Iron ore deposits at Dilband, Balochistan, Lead-zinc deposits in Duddar, Balochistan, gypsum, rock salt, limestone, dolomite, china clays etc in the Indus Basic, ornamental and construction stones in the various parts of the country and about 30 different gems and precious stone deposits in northern Pakistan.

Mineral industry in Pakistan shows that over the last few decades this sector has been allocated very small amount - 0.45% to 2.46% of the total public sector expenditure since first five year plan reflecting its contribution to Gross National Product (GNP) of just around 0.5%. The mineral resources of a country are valuable means and measures of its economic and industrial growth. These are still more important for Pakistan because of its favorable geological environment and a large number of mineral resources in the country. Considering that substantial scope exists for the development uncertainties, it requires Government support and recognition of mineral sector.

The Govt. is fully committed to making the mineral sector in Pakistan one of the most profitable for the country. During the current fiscal year, mining and quarrying sector has registered a growth rate of 5.7 percent as against 4.58 percent of last year. The increased growth was propelled by strong growths recorded in magnetite-30%, dolomite-26.1%, Limestone-25.2% and chromites. To make this sector thrive more in the upcoming year the Govt. has already started various initiatives which is evident from the discovery and development of world class copper-gold deposits in Chagai, Balochistan by Australian Firms that would fetch $500 million to $600 million per year during the lives of these mines Development of Thar Coal field, one of the largest good quality lignite deposits in the world on completion, would provide additional source of energy.


Important minerals in Pakistan:


1. COAL:
           

According to estimates prepared by the Geological Survey of Pakistan (GSP), Pakistan has total coal reserves of  185 billion tons, out of which 184 Billion tons are in Sindh – one of  the biggest good quality lignite deposit in the World.

Utilization of coal:

     Coal utilization in Sugar industry

·        There are 76 sugar mills in the country producing more than 10 million tons of bagasse.



PAKISTAN COAL RESERVES

Province
Resources Million Tons
          Status
Baluchistan :
          Hamai
76
Dev
          Sor Range-Degari
50
Dev
          Duki
50
Dev
          Mach-Abegum
23
Dev
          Pir Ismail Ziarat
12
Dev
          Bar khan – Chamalang
6
Dev
 Sub-Total
217

PUNJAB:

         Salt Range
213
Dev
         Markawal
22
Dev
              Sub-Total
235

SINDH:

        Thar Coal
                        175,506
Non Dev
        Sonda-Thatta
3,700
Non Dev
        Indus East
1,777
Non Dev
        Jherruck
1,823
Non Dev
        Lakhra
1,328
Dev
        Ongar
312
Non Dev
        Meting – Jhimpir
161
Dev
        Badin
16
Non Dev
Sub Total
 184,623

NWFP:
       Hangu / Orakzai
82

       Cherat / Gulla Khel
9
Dev
Sub Total:
90
Dev
       Azad Kashmir:


       Kotli
9

             Sub Total:
9
Dev
Total
                                             185,173




·        This bagasse is used mainly for burning in the boilers for producing steam in power generation to meet the electricity requirement of the mills

·        It has been estimated that the sugar mills based on coal need 4000-4500 tons of coal per day i.e. 1.0 to 1.5 million Coal per annum.



     Coal utilization in Cement industry.

·        Phased conversion of cement plants from fuel oil to coal is under implementation.                                   

·        Conversion of entire cement industry would require around 2.5 million tons of coal annually.




Production of Soft Coke for Foundry industries

Coal of Orakzai Agency is suitable for production of soft coke to meet the requirements of foundry and engineering industries


      Coal Washing

Indigenous coal contains high Sulphur and high ash contents due to which processing industry is reluctant to utilize it. To minimize such deleterious material in indigenous coal and to make it acceptable for processing industry, establishment of coal up-gradation/washing plants is needed.



     Manufacturing of Smokeless Coal Briquetters

·        A viable project to manufacture smokeless coal both for domestic and commercial uses as its calorific value (Btu/Rs) is highest as compared to wood, kerosene oil, Charcoal etc.

     Coal Utilization for power Generation

Can be used for power generation cement and other heat intensive industries.



     Use of Coal in Boilers

There are more than 4000 boilers in the country that use furnace oil or natural gas.Replacement of gas/oil with smokeless coal may be explored.

    

Gasification

Due to limited gas reserves in the country and to utilize Thar coal in best way, gasification is better-utilized option for Thar coal.

2. Copper

The significance of copper resources of Pakistan is widely known because of huge investment made in development of saindak copper deposit.   

       Potential Deposits

More than 1882.5 million tons of Copper reserves are found in Pakistan
      i) Reko Diq Copper – Gold Deposits



Location:  Distt Chaghi, Balochistan
Reserves:           837 million tons
.      Copper (0.64% with 50 millions tons)
                .       Gold (9 million ounces)
       
           

 ii) Saindak Copper – Gold Deposit Balochistan

                   -        Location:   40 km West of Reko Diq project
                -       Reserves;  400 millions tons
                -       Production:       15810 tons – blister Copper
                        (Per year   1.47 tons – Gold
                                        2.76 tons – Silver

Economic Benefits of Copper
         
                   -        Import substitution
                -       Indigenization of technology
-       Relatively cheaper copper available for export and for use in the local market for engineering and electrical cables
3. Zinc / Lead

More than 23.72 million tons of Zinc/Lead reserves are found in Pakistan. The Jurassic rocks of the Lasbela – Khuzdar Belt have the potential to host several WORLD CLASS’ zinc – lead ore deposits. Among the four better known deposits of Surmai Gunga, Dhungei Duddar is the most advanced.






i) Duddar-Gunga-Surmai Lead-Deposits

-        Detailed geo-scientific studies through mapping and drilling (46000 meters) an inferred plus indicated geological reserves of 14.31 Mt @  80.6 % Zn  and cut-off 3.2% Pb have been calculated for the Duddar Deposit using + 7% Zn Pb cut-off.

-       The resources of Duddar Deposit have been estimated at about 50 Mt.

4. Gypsum / Anhydrite

The gypsum resources in Pakistan have existence in at least three interesting areas in terms of their size, resource, quality, reserves and exploitability.

1.       Salt Range of the Punjab
2.       Kohat Banu Region of NWFP
3.       Suleman Range of D.G. Khan, Punjab

Resources:                     5-6 billion tons
Average Production:     384 metric tons per annum







Pakistan Gypsum Reserves


Province

Punjab
Deposits
         - Rakhi-Munh

         -Safed Koh-Rodo area (Central
          Suleiman Range)

         -Dadukhel – Mianwali area

         - Khewra
27 Mt.

15 Mt.


53 Mt
.
25Mt.
NWFP:

Dera Ismail khan

          -Saiduwali

          -Near Drazinda and Mughalkot

Kohat




20 Mt.

70 Mt.

4,442 Mt. (above surface)
472 Mt. (down to dip of 30 meters.
Balochistan

       -Near Spintangi

       -Mawand – Khattan

       -Barkhan – Chamalang


5 Mt.

20 Mt.

7 Mt.



Potential Investment Opportunities.

§  . Gypsum can be used as Corrector of Low Quality Tube wells     water.

§  Gypsum plaster sand blocks with gypsum mortar, may be considered for the construction of low cost houses.

5. Solar Salt

Bright prospects exist for the development of high purity solar salt facility around the coastal areas of Karachi. Solar salt so produced has export potential to the exponding southeast Asia Chemicals industries and for the growing industries established throughout.

6. Chromite Ore.

          Chromite occurrence is wide- spread yet its potential is far from being fully assessed judging from the favorable geological environment. For this reason, chromite deposits of Baluchistan and NWFP must be considered from a regional standpoint that could enable Pakistan to become a major exporter of chromite and /or ferrochrome.





Potential Deposits

i) Balochistan Chromite Deposits

-        In Pakistan, Muslim Bagh chromite deposits are of the major commercial source of chromite

ii) NWFP Chromite Deposits

-        In Dargai has been spectacular: estimated reserves 0.7 Mt of which 0.3 Mts are proven.
-       In Heroshah, open pit reserves of around 0.1 Mt have been proved.
-       Similary in Jijal-pattan and Chilas areas (Kohistan) Shunghail prospect appear to contain 0.2 Mt reserves.

7. Aluminum Deposits (Bauxite and Laterite)

Potential Deposits

          -        Reserves: about 74 millions tons
          -        Location:   Muzffarabad, Ziarat, Kalat, Khushabd





 Economic Benefits of Aluminum

Import substitution
Indigenization metals and row materials available in the market
Relatively cheaper, Aluminum available for export and for use in the local market for automotive, engineering and electrical




22 Mar 2013

metallurgy areas



·        There are four metallurgy areas
1- Physical metallurgy                           2- Chemical metallurgy
3- Extractive metallurgy                        4- Mechanical metallurgy

·        Metallurgy operations
1- Inspection and testing                        2- Corrosion Engineering
3- Nuclear Engineering                          4- Foundry Engineering

·        Foundry is a place where we melt and cast metals and alloys
·        Casting is a process in which we use a mold to reshape the metals and alloys
Steps of foundry operation:
·        First of all I need molten metal or alloy
·        Pattern/design is used to make mold
·        Molding
·        Sand testing/preparation
·        Inspection and testing of casting
·        Chemical composition verification
·        Microstructure examination

·        Smelting is a process in which physical and chemical changes takes place
·        Melting is a process in which only physical changes takes place
·        Pattern is a design used to make mold. It is of two types
1- Master pattern (Steel)                        2- Pattern (Wood)
·        Ingots are big pieces of metal or alloy




Basic steps in a foundry are
·        Melting
·        Molding
·        Casting
Foundry engineering setup


Foundry shops:

Two types of shops are
1-    Essential shops (Production areas)
2-    Auxialry  shops
·        Core is a mold used to get internally hollow shape