Principles of Cyclic-Flow Technologyin the Development of Deep Pits

S. Bukeikhanova, S. Kulniyaz, and S. LysenkoRSE "NC CPMRM RK", Republic of KazakhstanAbstract. In the paper developed and analyzed three variants of depositdevelopment using cyclic-flow technology and is recommended for theimplementation the first option, which provides for testing of the northern sectionwith the use of cyclic-flow technology (30% of soft overburden) and (70%) ofcyclical technology by using a simple road-rail transport.1 IntroductionDevelopment of deep open pit deposits at the present stage in Kazakhstan largelydetermined by the degree of improvements in technology and complexmechanization of mining and stripping operations on the basis of extensive use ofcyclic and continuous processes of extraction, transfer and storage of rocks.This problem is the focus of scientists, designers, and production and technicalpersonnel of such companies as "The National Center on Complex Processing ofMineral Raw Materials of the Republic of Kazakhstan" and large industrialcompanies, "Sokolov-Sarbaisky mining and processing production association","Corporation Kazakhmys", "Kazzinc" and a number of enterprises of iron ore andcoal industry, and non-ferrous metallurgy of the Republic of Kazakhstan. Themain parameters of some quarries are shown in Table 1.Table 1 Main dimensions of the pits “Aktogay”, “ Aydarly”( “Corporation Kazakhmys”)and “Kacharskiy”(JSE “SSMPPA”)Data UnitDepositSouthAktogayNorthAktogayAydarly KacharskiyRock mass million m3 712,7 51,1 1791,4 1457,5Overburden million tons 147,6 20,03 1168,5 1183,4Commodityoremillion tons 150,3 82,0 1657,0 910,6Length alongthe surfacekm 2 0,5 2,5 3,1Width alongthe surfacekm 1,5 0,5 2,5 2,9Depth m 550 250 890 76466 S. Bukeikhanova, S. Kulniyaz, and S. Lysenko

2 One of the Largest Quarries in KazakhstanKacharskyi open pit refers to the largest, deepest iron ore quarry in Kazakhstanand is a part of the "Sokolov-Sarbaiskyi mining and processing productionassociation" (Fig.1). Quarry develops the same name deposit in Kostanay region,54km from the city Rudniy.The quarry provides the options of crushing and conveying systems: ore inthree phases from the surface to the level of –270m with the issuance of ore to theloading hopper, for loading to rail transport and rock with a complex of in-linestacking for the issue of dumping of overburden rock external dumps, from thesurface to the level –120m, and the second to the level –135m. At horizon at

around –30m in an open pit provides two crushing transshipment nodes (rock andore), with a receiving hoppers on a concentrate horizon in the south-western sideof the pit.[1]Fig. 1 Kacharskyi iron ore quarry plan

3 Structure of the Kacharskyi DepositGeological structure of the Kacharskyi deposit is characterized by high power ofMesozoic-Cenozoic sediments (200-250 m), which cover the Paleozoic rocks andore complex.Principles of Cyclic-Flow Technology in the Development of Deep Pits 67Complex of Paleozoic rocks are sedimentary-volcanic suite, this suite containoriing, composed of marbleized limestones, sand and clay rocks, porphyries,albitophyres, tuffs and tuff breccia; much of the rock is partially or completelyreplaced by magnetite ores, preoriing and postmineral granite porphyries, skarnsand ores, formed in the contact area granite porphyries with rocks of sedimentaryvolcanicstrata; diabase porphyries dikes and albitophyres.The sedimentary-volcanic suite has undergone tectonic influences, throughwhich the ore zone and its enclosing rocks acquired a folded structure, sometimescomplicated by dumping of different directions.There are three separate parts on Kacharskyi deposit: the North and South,which are separated by a massive fault, and differ both in structure and form ofmineralization, and in composition of ores, and known as the second Northeasternpart.On the Northern part there is the great bulk of the explored reserves of thedeposit (90%). The ore zone has a tabular shape and occurs in accordance with thehost rocks of sedimentary-volcanic strata.A second Northeastern section is located in the immediate vicinity of theNorthern ore zone and is separated from her by barren rocks capacity of 100-150m. Deposit consists of two tabular ore bodies - Upper and Lower, separated bylayers of metasomatic rocks up to 150m. The minimum depth of undercutting ofthe roof of the Upper body 764m, maximum – 1130m. Average power of Upperbody is 74m, Lower body is 55m. Size of the deposit in terms of the latitudinaldirection 1400m, 1100m in meridian.Ore zone of the Southern section is curved strata in terms, extending from thesoutheast to the northwest and steeply falling at an angle of 60 degrees to thenortheast.Bedrock and composing deposits ore buried by a thick sequence of Mesozoic-Cenozoic sediments represented by clays and sands, sandstones and flasks. Thetotal capacity in the range of 130-200m (average 164m). Topography of Paleozoicrocks rather disjointed. Absolute elevations range from +10 to +80m.The covering Mesozoic-Cenozoic strata lies nearly horizontal layers, prettywell seasoned throughout the deposit area. The entire thickness of sediments canbe divided into three parts (top to bottom), each of which is characterized bycertain physical properties and mythological:1) sand and clay sediments (quaternary-Eocene) with an average totalcapacity of 45m;2) horizon of flasks and sandstones with interlayer with dense clays (halfrocks) – 81,7m3) quartz-glauconitic sands, variegated clays 51.3 m.The field is developed with rail (electrified with 10kV AC) and road transport.In the existing technology road transport is widely used in the deposit area - inquarry transshipment warehouses, railway - on the hauling of ore and rock withtransshipment warehouses and separate deposit up to +45m ore horizon after theformation of full-fledged train to the factory JSC "Sokolov-Sarbaisky mining and68 S. Bukeikhanova, S. Kulniyaz, and S. Lysenko

processing production association", and overburden on dumps. In-service fleetconsists of dump trucks BelAZ-75145, BelAZ-75121 with carrying capacity 120 t.and BelAZ-75131 with capacity 130 t. On rail transport is used traction machinestype OPA-1A and NP-1 and trailer dump cars 2VS-105, the number of which isusually composed of from 9 to 12. Mechanization of mining involves the use ofdrilling rigs SBSh-250MN and SBU-125 and excavators AKG-10, AKG-12,5,AKG-8I, AKG-6,3S, RH-120E, and on the loose strata ASh10/50 and Ash 11/70.Based on the geological structure of the array of soft overburden on theNorthern edge we have identified four areas top to bottom (Fig.2)[1,3]:Zone A - extends from the surface to the mountains. 142m, capacity - 120million m3. Characterized by a variegated clays, sands, flasks. Developingvariegated clays in the summer time there is sticking to the working surface ofmining equipment, in the winter –freezing of. In addition in winter time occursfreezing the top layer of variegated clays at a depth of 2.5 m, which createsadditional difficulties in their working out and require drilling and blastingloosening. It is possible to work out the Zone A by the complex flow technology,with observation of certain conditions in operating practices.Zone B - located between the marks +142m and +69m, capacity - 150 millionm3. Characterized by sandstones interspersed with clays. Developing ofvariegated clays prior explosive loosening of sandstones is required. For using inthe Zone B the cyclic-flow technology (CFT) there is a need to develop and test aspecific technology in mining.Zone C - located between the marks +69m and +45m, capacity - 50 million m3.Characterized by clays interspersed with layers of sand. It is possible working outwith the use of CFT.Zone D - located between the marks +45m and +30m, capacity - 30 million m3.Characterized by clays interspersed with layers of sand and conglomerates.Thus, bucket wheel excavators can be used when developing loose rocks inZones A and C. For working out with the inclusion of loose rock solid layers ofzones B and D requires the prior drilling and blasting rock loosening followed bycrushing to feed the complex CFT.Fig. 2 Section through the thickness of loose rocks in North-West border of the pitPrinciples of Cyclic-Flow Technology in the Development of Deep Pits 69

4 The Use of Cyclic-Flow Technology to Develop KacharskyiOpen PitThe project of reconstruction Kacharskyi open pit with increased productivity ofquarry in mining with 18 million tons to 23 million tons per year was developedby RSE “NC CPMRM RK” and Giproruda institute in 2008. The annual capacityof overburden grow up from 51 to 61 million m3, including unconsolidated rocksfrom 24 to 48 million m3.Table 2 Comparative data on the performance of the production program for thereconstruction of Kacharskyi open castData Unit 2008 2009 2010 TotalOre production byschedule of“Giproruda”million tons 18,2 18 18 54,2Ore production infactmillion tons 14,8 13,8 16,9 45,5Difference million tons 3,4 4,2 1,1 8,7Overburdenproduction byschedule of“Giproruda”

million m3 51,3 59,5 61 171,8Overburdenproduction in factmillion m3 36,7 43,7 50,4 130,8Difference million m3 14,6 15,8 10,6 41Including theproduction ofloose rock byschedule of“Giproruda”million m3 43,3 48,5 48,5 140,3Production ofloose rock in factmillion m3 25,2 24,1 18,7 68Difference million m3 18,1 24,4 29,8 72,3Including theproduction of rockby schedule of“Giproruda”million m3 8 11 12,5 31,5Production of rockin factmillion m3 11,5 19,6 31,7 62,8Difference million m3 +3,5 +8,6 +19,2 +31,370 S. Bukeikhanova, S. Kulniyaz, and S. LysenkoA sharp increase in current volumes of ore and overburden rocks must beaccompanied by a proportional increase in the number of mining and processingequipment to ensure its active edge of the mining operations. Simply increasingthe amount of available equipment on the quarry leads to considerablecomplication of mining management and the load on the existing transportcommunications.Therefore, project envisages the construction of two lines of theCFT for ragging and transportation of ore and rock overburden from open pit. Atthe same time, the project covers work out of loose rock that composes 80% oftotal volume of overburden and 72% of the rock mass, by traditional way - acomplex of railway transport and rope excavators.In terms of difficult modern economy situation, the company was not able tomake timely modernization of open cast and timely realization of productivitydevelopment was unsuccessful (tab.2). All these factors led to a reduction in thespace of the active forefront of mining that caused significant difficulties inmining process.If the lag of mining in three years was 16%, for the whole stripping – 24%, thenthe extraction of loose rock - more than 51%! Elimination of such backlog ofloose rock capping by existing park of mining equipment is almost impossible. Inorder to realize planned reconstruction of the career offered to use complex cyclicflowtechnology[2,4].In terms of market economy provision of stable operation in mining enterprisedepends on crucial factor - technical modernization of primary production. Withthe view of accelerate opening of iron ore reserves concentrated in the central partof the deposit can be used three options of technology of working the upper layersof the North side:Variant 1 – development of 30% of the total soft overburden by complexcyclic-flow technology (CFT), and 70% of overburden developed by excavatorrailcomplex according to existing scheme.Variant 2 – development of 100% of the total soft overburden using a set ofCFT;

Variant 3 – 100% of total soft overburden of the Northern pit edge worked outby excavator-rail complex according to the existing scheme.Based on the foregoing, the CFT complex provides the development of softoverburden of the northern edge of the pit in two ways:Variant 1 – development of soft overburden zone A by rotary excavatorcomplex , automotive inter-ledge loader, conveyors and stacker. Overburden of B,C, and D zones is fulfilled by excavator-rail complex according to the existingopen pit technology. for processing zone C available usage of rotary excavatorwith automotive inter-ledge loader after completion of works in Zone A;Variant 2 – development of soft overburden in zone A by rotary excavator,automotive inter-ledge loader, conveyors and stacker. Overburden of zones B, Cand D is developed by excavator-car complex with delivery of rocks to the mobiledock point with a self-propelled crusher, that is adjacent to conveyor line of rotorcomplex[2].Principles of Cyclic-Flow Technology in the Development of Deep Pits 71For Zone A scheme uses three bench mining (Fig.3), when the inby conveyor ison the middle bench, and the rotor excavator with automotive inter-ledge loaderdevelops all three benches without conveyor shifting. The width of the miningfield corresponds to the annual mining width. Inby conveyors are shifting once ayear. The total operating time may only be affected by the movement of the firstinby conveyor, because subsequent conveyors move during work of the rotaryexcavator. Taking into account the required annual productivity of overburdenzone A - 11.5 million m 3 / year operational capacity per hour of the complex is 2thousand m 3 / hour.Fig. 3 Technological scheme of working out three ledges 1 - bucket wheel excavator; 2 -inter-ledge loader; 3 - inby conveyorFor option 2, total overburden volume of zones A, B, C, D - 27 million m 3 /year that passes through the conveyor system and spreader of CFT complex.Development according to the second variant of zones B, C and D by roadcrushingcomplex delivery is made by stripping shovel mud of self-propelled(caterpillar) roll crusher pit dump with unloading at the transfer points (Fig.4).Download of crusher is produced by two trucks. Such a scheme of crusherdownload allows to improve efficiency of the complex by 10-15% due to theindependent work of excavator-car and crush- conveyor units of the complex.Crushed material is fed to conveyor that is also common for rotary complex.Fig. 4 Scheme of a boot of crushing conveying complex 1 – pit dump; 2 – bucket loader; 3– crusher hopper; 4 – rumble- grinding part of crusher; 5 – discharge conveyor; 6 – selfpropelledinter-ledge loader72 S. Bukeikhanova, S. Kulniyaz, and S. LysenkoCrusher is located either directly on the horizon of conveyor or on the adjacentlower horizon. As mining operations move eastward there is a shifting ofdownload crushing -conveyor unit complex.In order to accelerate input development of the reserves there is conventionaldivision of the working area of the Northern edge of the pit into two sections -East and West (Fig.5). Mining activities begin from the Western section. Thisenables further reducing the number of divisional conveyors twice.Fig. 5 Section through the thickness of loose rocks in North-West border of the pit

5 ConclusionThe dynamic modeling of the northern side of the quarry made on the graphicalbasis of construction phases of mining by rotary and rail complexes. The durationof each phase is determined by the productivity of mining complexes and thefactors that affect operational process of complexes.Comparison of the three options to develop soft overburden produced by theannual total discounted costs.The greatest effect is characterized by a variant with the lowest annualdiscounted costs. Table 2 shows the values of annual discounted costs by variants.

According to this criterion, the greatest effect is characterized by variant 1.