DUNITE & PYROXENITE

Indian Minerals Yearbook 2014 (Part- III : Mineral Reviews)

53rd Edition

DUNITE & PYROXENITE

(ADVANCE RELEASE)

GOVERNMENT OF INDIA MINISTRY OF MINES INDIAN BUREAU OF MINES

Indira Bhavan, Civil Lines, NAGPUR – 440 001

PHONE/FAX NO. (0712) 2565471 PBX : (0712) 2562649, 2560544, 2560648 E-MAIL : [email protected] Website: www.ibm.gov.in

December, 2015

17-1 DUNITE & PYROXENITE 17 Dunite & Pyroxenite

unite is a monomineralic ultrabasic rock The production of dunite was reported from only Dthat consists of more or less pure olivine. Dunite one primary mine which was in public sector located in typically contains 36 to 42% MgO and 36 to 39% SiO2. Chickmagalur district of Karnataka. In addition, produc- Olivine is a commercial source of magnesia combined tion of dunite was also reported as an associated with silica that is mainly used in metallurgy, fertilizer, mineral from public and private sector magnesite mines etc. Pyroxenite is also an ultrabasic rock that consists located at Salem district in Tamil Nadu and nominal of pyroxenes i.e., predominantly ferromagnesian production reported from Karnataka. Thus, 82% minerals other than olivine. There is a rising trend in production of dunite during the year was reported from use of dunite and pyroxenite in sintering and as a fluxing public sector and 18% was reported from private sector agent in blast furnace in place of dolomite. enterprises. Ninety nine percent of the total production was reported by four principal producers operating as RESOURCES many mines (Tables -3 to 5). In India, occurrences of dunite are reported in association with other ultrabasic rocks in chrysotile- Mine-head stocks of dunite at the end of the year bearing areas of Jharkhand and Karnataka; chromite- 2013-14 were 13,245 tonnes as against 13,793 tonnes at bearing areas in Odisha, Karnataka, Jharkhand & the beginning of the year 2012-13 (Table - 6). Nagaland; and magnesite-bearing areas in Karnataka & Tamil Nadu. As per the UNFC system, total resources Average daily employment of labour in the sole of dunite in the country as on 1.4.2010 are estimated at primary mine of dunite was 9 during 2013-14 as against about 185 million tonnes of which 17 million tonnes 5 in the preceding year. Prices of dunite are furnished in constitute reserves (about 15 million tonnes proved General Review on 'Prices'. reserves and 2 million tonnes probable reserves) and 168 million tonnes remaining resources. Dunite resources are located mainly in Tamil Nadu (63%) and Karnataka (17%). The remaining 20% resources are in Table – 3: Principal producers of Dunite, Jharkhand, Odisha and Nagaland. Reserves/resources 2013-14 of dunite are furnished in Table-1. Location of mine Name and address of producer The occurrences and production of pyroxenite are State District reported from Jajpur district in Odisha and Singhbhum (East) district in Jharkhand. However, no resource Tamil Nadu Magnesite Ltd* Tamil Nadu Salem estimates are available. 5/53, Omalur Main Road, Jagir Ammapalayam, Salem – 636 302, EXPLORATION Tamil Nadu. During the course of Platinum Group of Elements (PGE) investigations, GSI conducted preliminary Dalmia Bharat Sugar and Tamil Nadu Salem exploration in 2013-14 in the pyroxenite-bearing basic/ Industries Ltd., Dalmiapuram, ultrabasic/ultramafic rocks in parts of Andhra Pradesh, Tiruchirapalli-621 651, Gujarat, Karnataka, Nagaland & Tamil Nadu and also Tamil Nadu. during the investigation for chromite mineralisation in parts of Andhra Pradesh, Manipur & Odisha. The Smt.P.B.Baladevie,* Tamil Nadu Erode details of exploration are elicited in Table - 2. 14/51,52 Ramaiah Colony East, 2nd Street, Tiruppur-641 602, PRODUCTION, STOCKS AND Tamil Nadu. PRICES Dunite A.S.Shankarganesan,* Tamil Nadu Erode Dunite is mainly obtained as on incidental product 22-A,Kumar Nagar South, rd during mining of magnesite. Its production at 65,098 3 Street, Gandhi Nagar, Tiruppur-641 603, tonnes during the year under review decreased by 26 % Tamil Nadu. as compared to that in the previous year mainly due to decrease in market demand. * Producing dunite as an associated mineral with magnesite.

17-2 DUNITE & PYROXENITE otal T (A+B) resources (In '000 tonnes) 4800 4800 4800 8137 otal (B) 10995 14333 28058 31998 16415 17358 87273 93741 76158 83489 T 107963 116879 168231 185368 - - - - - 2157 8637 Reconnaissance 5773 4800 4800 4149 6121 8637 5664 6480 11007 21471 Inferred - 164 384 627 384 780 1 Indicated -- - - 23909 24516 Remaining resources Measured 140 607 780 70028 37569 24516 102190 107597 tates) - - ces of Dunite as on 1.4.2010 Pre-feasibility 4717 5267 4717 4717 STD221 STD222 ------(By Grades/S 130 130 STD211 STD331 STD332 STD333 STD334 Feasibility otal 3337 3940 3337 6468 (A) 17137 T able – 1: Reserves/Resour T - - 223 917 2243 Probable Reserves ------373 570 943 130 7466 1450 8916 3337 3718 3337 5551 6005 1326 7331 Proved STD111 STD122 14894 otal T tates amil Nadu Figures rounded off. T Nagaland Odisha By S Jharkhand Karnataka Unclassified Grade-II By Grades Grade-I All India: Grade/ State 17-3 DUNITE & PYROXENITE Table – 2 : Details of Exploration Activities for Dunite & Pyroxenite, 2013-14

Agency/ Location Mapping Drilling State/ Area/ Sampling Remarks District Block Scale Area No. of Meterage (No.) Reserves/Resources estimated (sq km) boreholes

GSI Andhra Pradesh Khammam Periphery of 1:50,000 300 - 197 Aerial reconnaissance stage & Chimalpahad 1:2,000 80 PGRS investigation (G-4) have ultramafic been carried out. The area complex exposes lithounits of the Chimalpahad ultramafic complex which is represented by pyroxenite, which are intruded within amphibolits of Khammam Schist Belt. Chromite occurs within the ultramafic rocks particularly dunite & pyroxenite. The work will be continued in 2014-15.

Prakasam Chimakurthi 1:12,500 85 -- 251 G-4 state investigation was Igneous Complex carried out to delineate the PGE potential zones. Chimakurthi Igneous complex consisting of pyroxenite, leuco- gabbro/norite, gabbro/norite, nepheline synenite and quartz monzonite. The preliminary analysis results have shown that the pyroxenite units are the favourable locales for PGE mineralisation. Gujarat Banaskantha Dhanpura 1:10,000 65 -- 140 During G4 stage, for PGE & REE Kengora investigation in ultramafic and felsic rocks, the basic suits of rocks comprise norite & pyroxenite occurs extensively in this area. The investigation has been completed. Karnataka Hassan Nuggihalli 1:2,000 0.75 -- 348 During PGE investigation, meta- Schist belt pyroxenites was found in mafic/ ultramafic rocks in some places. Manipur Chandel Mantum Ching - 4.89 --- During chromite investigation, block, ultramafic rocks particularly Kudengthabi area dunite & pyroxenite are seen.

(Contd.)

17-4 DUNITE & PYROXENITE

Table-2 (Concld.)

Agency/ Location Mapping Drilling State/ Area/ Sampling Remarks District Block Scale Area No. of Meterage (No.) Reserves/Resources estimated (sq km) boreholes

Nagaland Near Chokla, -- 129 - 21 Highly serpentinised dunite & Chipur, Pang peridotite host rock have been villages in Ophiolite identified during PGE belt. investigation. Odisha Dhenkanal Tulasipasi, 1:2000 1.14 23 - 23 During chromite investigation, Mahupal area chromatiferous dunite is observed.

Tamil Nadu Namakkal Tasampalaiyam -- 28 - 82 In Sitampundi anorthosite complex block in bands & lenses of chromiferous Sitampundi meta-pyroxenite & pyroxenite Complex were exposed. PGE mineralisation is mostly confined to chromiferous meta-pyroxenite bands. The investigation has been completed.

Erode Solavanur -- 10 929 - Mafic/ultramafic rocks ranging block in composition from dunite through gabbro, meta-pyroxenite, etc. were encountered during PGE (G3) investigation. Patches/lenses/thin linear bodies of meta-pyroxenite & dunite are also seen in Solavanur extension block.The investigation has been completed.

- do - Mettupalaiyam 1:12,500 120 -- 200 During G4 stage investigation for Ultra-mafic belt PGE, the lithounits exposed in the area are dunite, peridotite, pyroxenite, etc. The investigation has been completed.

Table – 4 : Production of Dunite, 2011-12 to 2013-14 (P) (By States) (Qty in tonnes; Value in `’000)

2011-12 2012-13 2013-14 (P)

State Quantity Value Quantity Value Quantity Value

India 38774 25450 88274 92841 65098 97197 Karnataka 3610 484 8750 1173 978 173 Tamil Nadu 35164 24966 79524 91668 64120 97024

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Table – 5 : Production of Dunite, 2012-13 and 2013-14 (P) (By Sectors/States/Districts) (Qty in tonnes; Value in `'000)

2012-13 2013-14 (P) State/District No. of Quantity Value No. of Quantity Value mines mines

India 1(4) 88274 92841 1(5) 65098 97197 Public Sector 1(1) 71495 83243 1(2) 53188 89161 Private Sector (3) 16779 9598 (3) 11910 8036 Karnataka 1 8750 1173 1(1) 978 173 Chickmagalur 1 8750 1173 1 600 80 Mysore --- (1) 378 93 Tamil Nadu (4) 79524 91668 (4) 64120 97024 Erode (1) 1520 1216 (2) 2555 1020 Karur (1) 109 49 --- Salem (2) 77895 90403 (2) 61565 96004

Figures in parentheses indicate the number of associated mines of dunite with magnesite. Pyroxenite The total production of pyroxenite at 2,985 tonnes Table – 6 :Mine-head Stocks of Dunite, 2013-14 (P) in 2013-14 decreased by 95% over the previous year (By States) as mines were not operating for want of environmental (In tonnes) clearences. There were two reporting mines during the year (Tables - 7 to 9). State At the beigining At the end of of the year the year The mine-head stocks at the end of the year 2013-14 was 10,094 tonnes as against 9,051 tonnes at India 13793 13245 the beginning of the year 2012-13 (Table - 10). Karnataka 4822 4409 The average daily labour employed in pyroxenite Tamil Nadu 8971 8836 mines in 2013-14 was 29 as against 200 in the previous year.

Table – 7: Principal Producers of Pyroxenite, 2013-14

Location of mine Name and address of producer State District

Shekhar Singh, Jharkhand Singhbhum(East) 52, Khasmahal, Gopalpahar, Tatanagar-831 002, Jharkhand.

Pravat Kumar Aditya Deo, Jharkhand Singhbhum(East) 605/39, Radha Colony, Khasmahal, Singhbhum (East) -831 002, Jharkhand.

17-6 DUNITE & PYROXENITE

Table – 8 : Production of Pyroxenite, 2011-12 to 2013-14 (P) (By States) (Quantity in tonnes; Value in `’000)

2011-12 2012-13 2013-14 (P) State Quantity Value Quantity Value Quantity Value

India 86031 33113 58562 17980 2985 806

Jharkhand 62747 19375 58562 17980 2985 806 Odisha 23284 13738 ----

Table – 9 : Production of Pyroxenite, 2012-13 & 2013-14 (P) (By Sectors/States/Districts) (Quantity in tonnes; Value in `’000)

2012-13 2013-14 (P) State/District No. of Quantity Value No. of Quantity Value mines mines

India 4 58562 17980 2 2985 806

Private Sector 4 58562 17980 2 2985 806

Jharkhand 4 58562 17980 2 2985 806

Singhbhum(East) 4 58562 17980 2 2985 806

Table – 10 : Mine-head closing Stocks of Pyroxenite, 2013-14 (P) (By States) (In tonnes)

State At the beigining At the end of of the year the year

India 9051 10094 Jharkhand 5504 6547 Odisha 3547 3547

17-7 DUNITE & PYROXENITE USES the other side, high silica content in olivine restricts its use in low silica iron ores because Dunite and pyroxenite are preferred as flux to high silica content creates excessive slag dolomite as a source of MgO in sintering and also formation in the furnace. in Iron & Steel Industry. Main benefits of olivine over dolomite in slag conditioning are higher MgO Dunite is well-suited as a refractory material content, no requirement of preheat treatment low due to its low and uniform coefficient of thermal LOI, reduced energy consumption, lower coke expansion. Besides, dunite exhibits properties consumption, reduced slag volume and lower CO2 such as, good resistance to thermal shock; spalling emissions. Presence of higher amount of silica in and slag attack; high green strength; and dolomite leads to lower sinter basicity (i.e. CaO/ resistance to metal attack. Dunite, calcined in 0 SiO2) at around 2.5 than 3.5 of dolomite and the rotary kilns at 1,650 C increases its refractory phases in sinter change to those having better and foundry applications. Other uses of olivine reducibility. The net result is a reduction in the are as loose-grainshot blasting abrasive, filtration resistance of the cohesive zone to gas flow in the media, in mineral wool production, filler in blast furnace leading to drop in fuel rate and higher speciality paints, asphalt, mastics and weighing productivity. In addition, the magnesium silicates agent in concrete oil production platforms. Olivine do not call for calcination (unlike the carbonates) also contributes magnesia and iron as nutrients and thus lowers energy requirement in the blast to the soil. furnace. SPECIFICATIONS Olivine helps to condition the slag as well as to control the basicity through reduction of alkali Olivine should contain 45 to 51% MgO, recirculation. Its higher reaction temperature 40 to 43% SiO2, 7 to 8% Fe2O3, 0.2 to 0.8% CaO and reduces low temperature breakdown and swelling 1.8 to 2% Al2O3 and TiO2, MnO, Cr2O3, NiO and of burden; thus, maintaining permeability and CaO for various uses. For blast furnace reducing coke consumption. The olivine may be use, olivine should contain 47 to 48% MgO with added directly to the blast furnace charge as lump 10 to 40 mm lump size. For foundry use, the size (10 to 40 mm), sinter feed (3 to 6 mm), or mixed should be AFS 20, 30, 60, 90, 120 and for flour, with low silica iron ore fines and pressed into filler and fertilizer grades, size recommended is up pellets. When lump is added directly to the to 0.8 mm, up to 0.02 mm and less than 0.1 mm, furnace, olivine can replace limestone partly and respectively. dolomite flux in the reduction of iron ore. In As per the end-use grade classification, the comparison with dolomite, olivine has higher MgO reserves of 'fresh' and 'weathered' dunite have content (requires less material for a given MgO been classified as Gr. I and Gr. II, respectively. level), MgO: SiO ratio (allows MgO levels to be 2 However, recommendations to assign chemical raised without changing the basicity of the slag) specification to these grade based on the and lower LOI, i.e., 0.3-0.7% (conserves the experience of Tata Steel Ltd and GSI have been energy required to drive off unwanted carbon incorporated which is provided below: dioxide). As a sinter feed, olivine reduces the sintering temperature as much as 1000 C; thus, Grade MgO% SiO % LOI% Cr O % producing harder sinter which in turn generates 2 2 3 less fines. Olivine is added directly to the iron ore as flux during the production of pellets lowers Grade-I 41.12 33.41 12.74 below 1 melting cost by swell less, reducing more quickly Grade-II 32.44 29.16 24.09 – and have a narrower melting range. However, on

17-8 DUNITE & PYROXENITE For steel and alloy manufacturing, pyroxenite about 24% as compared to that in the previous lumps as well as fines/dust are being consumed. year. Iron & Steel Industry was the major The specifications of pyroxenite as per Indian consumer of dunite and accounted for about 74% Ferro Alloys Producers Association (IFAPA) are as follows: share in 2013-14. The remaining 26% was consumed in the Refractory Industry (Table - 11).

Grade MgO% SiO2% Al2O3% CaO% Cr2O3% Table – 11: Estimated Consumption* of Dunite Grade-1 34 min. 36-39max. 1-2 1-3 min. 1 min. 2011-12 to 2013-14 (By Industries) Grade-2 34.38 35 1-2 1 max. 3.5 - 6 (In tonnes)

BIS has adopted IS: 7297-1974 (reaffirmed 2014) Industry 2011-12 2012-13(R) 2013-14(P) as specification for olivine sand and flour for use All Industries 41700 38800 48000 in steel foundries. Iron & Steel 30500(4) 26100(4) 35300(4) CONSUMPTION Refractory 11200(5) 12700(6) 12700(6) The Iron & Steel and Refractory Industries Figures rounded off. Figures in parentheses denote the number of units in organised are the main consumers of dunite. Consumption sector. of dunite in the organised sector was at 48,000 (*Includes actual reported consumption and/or estimates made tonnes in the year 2013-14, which increased by wherever required).

17-9