KOTA STONE MINING – SOME CRITICAL ASPECTS

A. Hussain

Kota stone mining and its dressing as value addition process is one of the major industry in Kota and Jhalawar districts of Rajasthan. It is a minor mineral and covered under Rajasthan state minor mineral concession rules and is used as a comparatively cheap flooring medium. The present trend is to grant mining lease rights to the applicants for 4.0 Ha area under the state mineral concessional rules. The stone deposits are more or less horizontal sedimentary layers lying under variable thickness (10m to 30m) of overburden composed of different rock combinations importantly, shale, high silicious non laminated lime stone, basalt or soil and subsoil profiles. The ore winning technology is semi­mechanized involving waste removal by semi mechanized affairs and stone by manual system in open pits.

In this article, we have tried to analyze the financial implications of the activity and its counter effects on the current land use pattern. We have tried to focus on the measures very necessary to restitute the balance for a sustainable, agrobased culture and mineral winning activity.Kota and Jhalawar districts of Rajasthan jointly have proven reserves of about 100 million tones of acceptable quality of floor grade splittable lime stone, known widely as kota stone. Current trend of yearly mining of 55 to 60 lakh MT stone requires about 100 hectares land, which is primarily under agriculture providing biennial crops.

The present mining activities almost destroy the land and transform it into proven waste land. This assessment do not cover the land which is blanketed with solid stone slurry released from the stone cutting and polishing industries. Almost a sizable cultivatable land has been sacrificed on the altar of mining industry and this process is still in force. This is a serious environmental issue which need a specific and positive corrective action. Solutions are not difficult and financial resources to carry out such restoration programmes are neither hard to be located. A land bank comprising different restored areas can be built up and later on extended to the original land owners in proportion to their land requisitioned for mining activity. Any such action will reduce the pressure on land cost inter­alia help in bringing down the cost of production and compensate the restoration costs born by the mine owners. The financial analysis discussed here pertains to a typical mining, but stretching this canvas over other similar mining activities is not an inhibition, except variation in dimensions.

GeologyDeposits located in Kota district are characterized by North West – South East trending strike ridges and plateaus in the northern parts and broad open valley occupying the southern half portion. The easterly flowing Amjar river along with its tributary nalas drain the southern portion and consequent pattern is dendritic in the plain areas while it is sub trellis in the area occupied by strike ridges. The climate is semi – arid with moderate annual rainfall. The temperature falls below 100C in the winter while it reaches 450C in the summer.Regional geology is given in following table

Period Geologicalcycle

group Sub group Formation Lithology

1 2 3 4 5 6Mesco toNEOProterozoic

VindhyaSupergroup

LowerBhander(Lakheri­Singoli;)LimestoneformationsGanurgarhShaleFormation

Limestone(Dolomite)Shale withlimestoneBends

Upper rewa(Taragarhfort­umar)sandstoneformation

Quartziticsandstonewith grittyandconglomeratebands

Rewa Group Thiri(Ratangarh)Shale

Shale withlimestone

KaimurGroup

Chittaurgarhfort (Dickin)Sand stoneformation

Quartziticsandstone

Semi Group Suket ShaleFormation

Shale,Limestoneinterbedssandstone

The Vindhya Super group of meso to neo­proterozoic age, represented by its four group is exposed in these areas. The oldest semri group is subdivided into the khorip sub group, and is represented by the Suket shale formation, which is an assemblage of shale with interbands of Limestone. The shale are fissile, soft and micaceous, thinly bedded to laminated.

The Suket shale is conformably overlain by Chitorgarh fort sandstone formation of the Kaimur group. The Kaimur sandstone is dirty­white to brown with blotches of pink and streakes of red, purple and grey quartzite sandstone and contains 90% detrittal quartz and in general is fine grained, thinly to thickly bedded and massive.

The Rewa group is represented by the Jhiri shale (Ratangarh shale) and the upper Rewa sandstone (Taragarh fort sandstone) formations, conformably overlies the Kaimur sandstone.

The Jhiri (Ratangarh Shale) is thinly bedded to laminate and splintery in nature and pale yellow to Khaki green in color. It contains thin bands and lenses of clay and dolomitic limestone. Limestone is often stromatolitic in pockets.

The Taragarh (upper Rewa) sandstone is coarse grained and conglomeratic at base. It is a massive, quartzite sandstone containing more than 95 percent detrital quartz and is dirty

white light grey and pinkish in colour.The assemblge conformable overlying the Rewa group is the Bhander group,

represented by the Ganurgarh shale, lower Bhander (Lakheri) Limestone, Lower Bhander (bundi Hill) sandstone and the Sirbu shale formations.

The Ganuragarh shale is brick­red, purple to olive green, splintery, thinly bedded to Laminated and is intercalated with bands of limestone. It shows sporadic mud cracks. The Ganuragarh shale grades on to the lower Bhander Limestone which is generally ash­gray, choclate, pink and reddish­brown, massive and non­crystalline rock and dolomitic in composition.

The Lower Bhander sandstone (LBS) conformably overlies the lakheri limestone and comprises three litho units in the area, namely lower sandstone, middle shale and upper sandstone. The lower Bhander sandstone is ortho quartzite in nature with more than 95 percent detrital quartz. A few grains of feldspar, chert, tourmaline, zircon and flakes of mica are present. The shale is pale grey, olive green, brown and khaki, thinly bedded and inter ciliated with sand stone and siltstone.

The youngest litho unit in the area is the shirbu shale overlying the lower Bhander sandstone and occupies small area. It is a soft fissile, grayish brown and buff colour rock.Bedding is well developed in all litho units and variety of sedimentary structures such as ripple marks, parting lineation, sun cracks, load and flute cast and rain prints present in the rocks suggest their deposition in a shallow marine basin under fluctuating conditions. The beds are mostly horizontal with occasional rolls, a NW­SW trending axial trace of a major asymmetrical anticline passes through the southern part of the area and closure of this fold is located 2 kms northwest of Dippura in the toposheet No 45 P/9.

The Suket shales in the area are quarried, dressed, polished and sold as Kotastone for flooring, vindhyan sandstone (LbS) is extensively quarried for construction material while the lakheri limestone is and for lime burning.

Requirement of land for mining.

Kota stone production retains a direct relationship with surface land requirement function. An area of 100’x100’ in kota district deposits is capable to yield about 12.0 lakh sq.ft. of Kota stone slabes to 18.0 lakh sq.ft., and on average the yield comes to 16.0 lakh sq.ft. In case of Jhalawar district the average yield for a similar area is about 13.0 lakh sq.ft. of Kota stone slabes, considering non viability of top two sacks in the later case. Assuming a production mix in the ratio of 40:60 between Kota district and Jhalawar based deposits, we may consider an uniform yield of 15.0 lakh sq.ft. for 100’x100’ surface area.Yearly requirement of land for annual Kota stone slabes production is given in Table – A.

Table AYearly surface land Requirement for Kota stone slabes production

Year Production ofstabes in lakh MT

Lakh Sq. Mtr. Surface landrequirement (Hq.)

2006­07 30 300 202007­08 40 400 272008­09 45 450 30

2009­10 40 400 272010­11 50 500 342011­12 55 550 37

The land requirement is further compounded with additional requirements for waste storage facilities. Considering a waste Dump, having the dimensions given in following figure­

Figure (Water Dump)

Dimensions given in figure and 380 angle of repose, the volume of the dump can be evaluated as under.Area of upper deck = w1 , l1Area of bottom deck = w2, l2Volume = H x l1w1 + l2w2

2Height of Dump considering 380 angle of repose will beH = 0.39 (D­W), whereD is the shorter base dimension, andW is the shortest top width, normally 3.0 to 4.0 Mtrs., depending upon the width of trucks engaged in waste movement.

We may roughly estimate the waste retention capacity for 1.0 Ha. Surface land of rectangular formation having 1:1.5 ratio in its width and length. In such case the shorter dimension will be 80.0 Mtrs, and the dump height would be H=0.39(D­3)=0.39(80­3)=30 Mtrs. This height will further reduce considering lowering of angle of repose during rainy season. Apart from this, the capacity reduces considerably for waste dumps entirely composed of soil and sub­soil, as is the case of many properties located in Jhalawar district. The maximum height of waste dump on 1.0 Ha surface land may be considered to be 25.0 Mtr, taking into account all these factors.Where, as l2, w2 = 10000 sq.mt.

l1, w1 = (120­2.6H) x W= (120­2.6 x 25) x 3 sq.mt.=165 sq. mtr.

Dump volume will be165 + 10000 cu. mtr.

25 x 2

= 1,27,000 cu. mtr.

Yearly requirement of surface land for waste disposal for five years is given in table BTable – B

Yearly surface land requirement for waste disposalYear Production of

Kota stoneStripping

ratio (M3 persq. m)

Volume ofwaste

disposal (lakcu mtr.)

Landrequirementin Ha.

Mt. (in lakh) Sq. Mt. (inlakh)

2006­07 30 300 0.25 45 352007­08 40 400 0.25 60 472008­09 45 450 0.25 68 532009­10 40 400 0.25 60 472010­11 50 500 0.25 75 592011­12 55 550 0.25 83 65

Table – C gives total annual land requirement to sustain production parameters.

Table – CKota stone production v/s land requirements

year Production inMT (in lakh)

Landrequirement formining Ha.

Landrequirement forwaste disposal

Ha.

Total landrequirement Ha.

2006­07 30 20 35 552007­08 40 27 47 742008­09 45 30 53 832009­10 40 27 47 742010­11 50 34 59 932011­12 55 37 65 102

Land value and cost of landThe current land use pattern around Kota stone deposits in Kota as well as Jhalawar districts of Rajasthan is agriculture and from crops farming point the Black Cotton soil is highly productive subject to availability of irrigation sources. Presently these areas are not connected with irrigation networks and therefore, agriculture is rain fed. The dominant crops during Kharif season are Soyabean, Maze and Sorghum, while Rabi carries coriander (Dhaniya), Mustared and wheat. During Kharif season 85 percent cultivation is of Soyabean and Rabi is equally

divided for coriander and mustard cultivation. The productivity of crops per hectare land and its value from the current year marketing prices is given in Table –D.

Table – DCrops pattern and value of crops. (per Ha. cultivable land)

crops Production in MT/Ha. land Value of crops as per currentMarket prices

Soyabean 24.0 Kwtl Rs. 3500/kwtl (Rs. 84000)Dhania 24.0 kwtl Rs. 4000/kwtl (Rs. 96000)Mustard 50.0 kwtl Rs. 3500/kwtl (Rs. 175000)Total for both crops 75.0 kwtl Rs. 2,71,000/­

With the loss of cultivatable land every year, there is a loss of agricultureal output, and its cumulative effect becomes a substantive loss to local agro­based economy. Economical losses in the agricultural sector due to land use pattern shifting are shown in table – E.

Table – ELoss of Agriculture due to shift in Land use pattern

Year Land shifted from agricultureto mining works in Ha.

Loss of agriculture in Rs.2,71,000/Ha.

2006­07 55.0 1,49,05,0002007­08 74.0 2,00,54,0002008­09 83.0 2,24,93,0002009­10 74.0 2,00,54,0002010­11 93.0 2,52,03,0002011­12 102.0 2,76,42,000

Another important aspect of this pattern change is convertion of farming category employment into a mining category as semi­skilled or non­skilled mine worker. The farmers and their family members, who sold their land to mine­owners, become ousted from their properties and rehabilitated as working hands in the mines, purchasing their lands.Considering the average JOT (Agricultured land per khata holder) is 6 Bigas (1.0 Ha), and each family consists of atleast four working members, the loss of land and unemployment of working adults is given in table – F.

Table – FYear Loss of farming land

in Ha.Families Displacedfrom farming

Working handsbecoming

unemployed infarming sector

2006­07 55 55 2202007­08 74 74 2962008­09 83 83 3322009­10 74 74 296

2010­11 93 93 3722011­12 102 102 408

Farming displacement and mining rehabilitation scenario –Most of the land owners adopt mining works after disposing off their prime agricultural lands, where they are paid as per applicable piece rates compatible with minimum wages put into force by central ministry of labour from time to time.Table – G, shows the extent of miner’s employment (Excluding services, administrative and other categories) for the Kota stone mines, presently in operation in Kota and Jhalawar districts.

Table – GEmployment of Miners in Kota Stone Mining works

Year Production inMT.

Employment

Unskilledcategory

Semi­skilledcategory

Total

2006­07 30,00,000 3000 7,50,000 7,53,0002007­08 40,00,000 4000 10,00,000 10,04,0002008­09 45,00,000 4500 11,25,000 11,29,5002009­10 40,00,000 4000 10,00,000 10,04,0002010­11 50,00,000 5000 12,50,000 12,55,0002011­12 55,00,000 5500 13,75,000 13,80,500

The applicable wages structure for different categories of workmen employed in the mines, is given in Table – H.

Table – H(Applicable Minimum wages)

Date Minimum wages rate(Rs/day)Unskilled category Semi­skilled category Skilled category

01­04­2010 186 224 26501­04­2011 205 247 28701­10­2011 212 256 29701­04­2012 223 270 31301­10­2012 231 279 32401­04­2013 236 285 324

Before making a comparision of gains and losses in the individual farmer’s income post disposal of his agricultural land, it is worthwhile to take a stock of his agricultural income, before land sale out.Table – I shows the yearly income of a single farm khata holding family of four working members, which comes to­

Table ­ ICorriander 24 kwtls x Rs. 4000/kwtlMustard 50 kwtls x Rs. 3500/kwtlTotal value 2,71,000/­

This income, after making deductions for seeds, ploughing and other incidental expenses (other than labour wages) becomes, Rs. 2.00 lakhs, but to some extent the deductions are compensaled by the sales of fodder, stalks etc. However, the total period for which the employment is kept in force is only six months (Three months effective period for each farming session) the total man power engagement would be about 200 working days (800 Man days), and accordingly the wages per Man day comes to Rs. 260/­ day. The family members are free to work for other remunerative jobs after inputing 200 working days into farming works, where the monetary gains will be in addition to farming income.The analysis shows that after disposing his cultivatable land, farmer does not make any gains as far as monetary levels are concerned. The king of land becomes a begger after disposing off his land, and his status from farmer has been brought down to land less labourer and once the mining work is over, he does not have any place to work and in all probability will become a riksha puller in the nearby town or city to feed his family.

Mining CostKota stone mining is a semi­mechanized operation, whereas removal of overburden is carried out by mechanized means, employing medium size hydraulic excavators and tippers. Soil and sub­soil are removed without resorting to Drilling blasting and underlying hard overburden is drilled – Blasted. Mining cost can be classified into five sub­heads.

1. Land cost2. Development cost3. Cost of channel making, Dressing of slabes, stacking, loading of finished material into tippers

and their unloading into stock yards.4. Stock yard maintenance.5. Dewatering and other over­head expenses6. Royalty

1. Land costAs mentioned earlier, prime farming land is purchased from farmers for mining and waste – disposal. The current land prices, as applicable in Kota and Jhalawar districts are given in table – J.

Table – JCurrent Land purchase prices.

Distt. Kota Rs. 24.0 lakhs/Ha.Distt. Jhalawar Rs. 60.0 lakhs/Ha.

Mine owners in case of Jhalawar deposits are prepared to pay substantirely more in comparasion to Kota deposits, because of soft overburden which does not require Drilling.

Blasting. As discussed earlier the surface area of 100’x100’ will generate about 15 lakh sqft. Kota stone slabes. For all purposes we may consider weight of 15 lakh sqft. Stone as 15000 MT.On this scale an area of 1.0 Ha. surface land will lead to 1,50,000 MT or 15.0 lakh sq. mtr stone. To win this quantity of lime stone, on an average 2.50 lakh cu Mtr. Overburden of different nature has to be removed and stacked into waste dumps.To win 1,50,000 MT lime stone, the cost of land will be as under.

S.No. Objective Required Land(Ha.)

Cost of Land(Rs. In Lakh)Kota Distt. Jhalawar Distt.

1. Mining 1.0 24.00 60.002. Waste Disposal 2.0 48.00 120.00

Total 3.0 72.00 180.00

The mine owner has to purchase land for mining, at the first stage of mining activity.

2. Development Cost –

Development phase of mining include removal of overburden and its final disposal into waste banks. This activity requires drilling and blasting in Kota district deposits, while Jhalawar district deposits almost do not need blasting, or to a negligible status.The current cost of Drilling and Blasting is Rs. 20/cu. Mtr (Rs. 8/MT) excavation cost in relation to prevailing diesel prices is given in Table K.

Table – KCost of Excavation

Year HSD Rates Rs/LT(Averages)

Cost of waste loadingand TransportaticRs/Cu.M

Cost of O/B RemovalRs/Cu.M

2013 51.00 65.00 85.002012 44.00 60.00 80.002011 41.50 58.00 76.002010 38.00 50.00 65.002009 38.00 50.00 65.002008 35.00 48.00 63.002007 32.00 45.00 60.002006 31.00 45.00 60.002005 29.00 45.00 60.002004 25.00 40.00 55.002003 21.00 40.00 55.00

Cost of Development for 1.0 Ha. Area for Kota and Jhalawar districts are given in the following Table L.

Table – LS.No. Activity Rates Rs/M3 Total Cost of

Excavation (2.5Lakh Mtr) (Rs in

Lakhs)Kota Jhalawar

1. Drilling ­ Blasting20.00 46.00 ­2. Excavation 85.00 212.50 212.50

Total 105.00 258.50 212.50

In Kota District deposits, soil/subsoil segment of 25000 Cu Mtr (Average thickness 2.5 Mtr) do not require Drilling – Blasting and therefore has been curtailed from total waste quantity of 2.50 lakh Cu. Mtr. For drilling blasting expenses application. The extra cost of Rs. 46.00 lakhs in cost of Kota district deposits are partly compensated by lower cost of land.

The present trend in some of the mines is to straight – away sell part or fully developed areas.

3. Cost of channel cutting, dressing of slabs, loading and transportation of finished material to the stockyards.

Kota stone exposed surfaces are given 15 cms to 20 cms deep cuts at the intervals of 60 cms with the help of electric disc cutters, Semi­skilled workmen are engaged to cut, dress and stack different size stone slabes in the pit floor, from where slabes are loaded into trucks and transported to the surface stockyards.The present cost of this activity is Rs. 5.50 per sqft of the readily salable product, and in terms of weight will be Rs. 550/ MT. (Rs 55 per sq. mtr.)

4. Stock Management

Various works including stacking, sizing, and other allied chores carried out in surface stockyard cost about Rs. 60/MT

5. RoyaltyState charges Rs 100 per MT as royalty over the dispatches.

6. Misc ExpensesMine owner bear about Rs. 30 to 35 MT for dewatering, misc. expenses.

The total cost of mining 1.0 Ha. Area, generating 150000 MT (15.0 lakh sq. mtr) Kota stone at the prices given in this head would be as under

Table – MMining cost

S.No. Description Cost in Lakh RupeesKota Distt. Jhalawar Distt.

1. Land Cost 72.00 180.002. Dev. Cost 258.50 212.503. Channel cutting etc. 825.00 825.004. Stock, Management 90.00 90.005. Royalty 150.00 450.006. Misc. 45.00 45.00

Total 1440.50 1502.50

This actual cost is to be added further towards interest on the capital and necessary surplus.The average current sale price is Rs. 1600/MT and total revenue generation out of 1.0 Ha. Enterprise would be 2400 lakhs.

WHO GETS WHATThe owner purchases 1.0 Ha land for mining after investing 24.0 lakhs (Kota District) or 60 lakhs (Jhalawar District) respectively and mines out 1,50,000 MT of Kota stone at an expenditure of 1500 lakhs in a period of one or two years and obtains 900 lakhs out of this enterprise as gross surplus. This is a surplus after clearing govt. taxes, royalty, labour payment and other expenses but do not include provisions for interest on capital, risk management, insurance etc. A summary profit and loss account of 1.0 Ha mining operation in terms of financial implications would be somewhat as under –

1. Owner receives gross amount of 900 laks after making an expenditure of 1500 lakhs in one or two years perioed.

2. State earns 150 lakhs as royalty3. Workmen earns 130 lakhs for their workmanship.4. Loss of agriculture land is 3.0 Ha.5. Loss of crops is Rs. 8.13 lakhs per year on sustained basis.

This clearly shows that the maximum gains received out of this enterprise is the mine owning company, who receives about 40% of the value of the deposit laid down under mining operation and the worst looser is the land owner, who has changed his occupation and earned the same wages, which he used to earn before land ownership changed hands. In this bargain he lost valuable land providing earnings on sustainable basis, and opted a miner’s job with uncertain future.

What should be done.The scenario as highlighted can’t be called a likable sequence of events. What needed is to compensate the land owner for his permanent losses by providing properly restored mined out areas with adequate soil – sob soil blanketing over the fills and irrigation facilities extended from the mind out areas water resources. This is not difficult and can be achieved by resorting to an

eco friendly mining sequence accommodating proper stripping, banking and reuse of soil – subsoil, planned waste disposal, and utilizing quarry water for irrigation through pipes and channel networks. The owning company should bear the cost of this activity, out of their margins and thus help the Ex. Land owner to achieve a part of his sustainable income, which was lost in the first stage of mining sequence.

A. Hussain