采矿翻译,矿业翻译,矿业合同翻译 采矿技术翻译,英文版

发布时间:2011-07-08 18:08:27
 

366翻译公司采矿翻译,矿业翻译,矿业合同翻译 采矿技术翻译,矿产翻译案例

7.2.2 Open Pit

Golder’s report contains details of all field work completed by Geo-Logic Solutions, as well as all analysis conducted by Golder to evaluate large and small-scale slope stability. The report contains background information, the principal results from field and laboratory measurements, and a description of the major geotechnical domains in each of the proposed pits. It provides recommendations for large-scale open pit design as well as bench scale design. It also describes operational issues of a geotechnical nature and contains a description of instrumentation and monitoring that will help optimise future mine design and operation.

Golder considers that the field and laboratory test work carried out by Geo-logic Solutions falls within the suggested levels of geotechnical effort and target levels of data confidence as defined by the Guidelines for Open Pit Slope Design (2009) for a feasibility study. The subsequent analysis carried out by Golder and described in this report are sufficiently accurate to facilitate feasibility design of open pit slopes at the Husab mine Project. Golder has described and discussed the geotechnical aspects of mine design to a level of detail commensurate with a bankable feasibility study for a large open pit mining project.

7.2.2.1 Scope of Work

• The scope of work for the open pit slope design included the following activities

• A study and assessment of all available information supplied, including the following

_ All field data collected by Geo-Logic Solutions

_ A study of all previous geological, hydrogeological and geotechnical reports

_ The assessment of all laboratory testing data to develop an understanding of the intact rockproperties

_ The assessment of the rock mass ratings from borehole core including the Geological Strength Index (GSI), Rock Mass Rating 89 (RMR89)

• A review of surface water and groundwater conditions that could affect the design of the mined slopes which includes an assessment of piezometric surfaces and pore pressure distributions within the pit slopes

• A review of geological structural data to assess the potential for kinematic instability

• A site visit by a senior rock engineer to assess geotechnical core drilled for the two open pits; identification of significant geotechnical domains that will impact slope stability and mine design

• Determination of geotechnical design input parameters relevant for basic mine design, including intact rock strengths, rock mass strength, Hoek-Brown parameters (mi, mb, s and a), and Mohr-Coulomb parameters (c’ and φ’)

• Statistical analysis of input and output parameters to facilitate sensitivity studies on inter-ramp slope stability for each major domain

• Slope stability analyses using the SLIDE algorithm to determine stable inter-ramp slope angles for basic mine design Calibrate design by conducting checks with finite element package PHASE 2.0 version 7.0

• Provided recommendations on the following slope design architecture

• Bench configuration which would include bench height, bench width and bench face angles

_ Stack heights, inter-ramp angles for the different formations

_ Overall slope angles

• Assess slope configuration scenarios defined as a) low risk (conservative), b) medium risk (intermediate) and c) high risk (aggressive)

• Provide a report outlining all the stability analysis design inputs, models and recommendations for the design of the slopes for the two open pits.

Three major geotechnical domains have been identified, based on the predominant material type:

• Sand

• Calcrete

• Fresh Rock.

The geotechnical parameters used for stability analysis are outlined in Table 7.2.1, Table 7.2.2 and Table 7.2.3 below:

冶炼专业:采矿翻译,矿业翻译,矿业合同翻译 采矿技术翻译,矿产翻译案例

8.3.9 Underflow Re-leach

The re-leach circuit was operated from 18 May 2010 until the end of run 3. A bleed stream of the thickener underflow, roughly one third of the total flow, and CIX barren (1:1 w/w ratio) was fed to a 17 L agitated leach tank. The re-leach was operated at 40°C. Pyrolusite was added to target an ORP of 500 mV. The product slurry overflowed into a bucket which was fed to the filter in hourly batches.

8.3.10 Filtration of Leach-End Residue

The fines thickener underflow and screen oversize were combined and diluted to approximately 60% with CIX before gentle blending and flash flocculation. At the end of run 3, the re-leach product was also fed to the filter. The combined slurry was fed to two Larox PF01 filters. Filter operation was adapted to simulate belt filter efficiencies which are to be used in the commercial plant.

Three separate washing stages were undertaken during run 3. Equal volumes of CIX barren liquor was used for washes 1 and 2 and Perth tap water was used for wash 3. Wash 3 volume (Perth tap water) was reduced during the run by ~75% to aid the bleeding of undesirable salts in the filter cake moisture. The formate and all washates were combined and fed to the screen as dilution to target a screen undersize density. Moist filter cakes were weighed, sampled and stored.

8.3.11 Continuous Ion Exchange

Pregnant leach solution (PLS) from the fines thickener overflow was pumped to a surge tank mounted on scales ahead of the CIX adsorption circuit. CIX barren (cell 11 discharge) was recycled to the re-pulp, screening and filtration stages. The adsorption circuit consisted of 11 stages and the resin moved counter current to the PLS in nitrogen agitated cells, set up in a cascading train. The volume of each cell was ~11,5 L. Humidified nitrogen was sparged at 2 to3 L/min to each cell. The solution overflowed from one cell to the other whilst resin was retained in the cell using a 425 μm screen placed in the opening of the overflow.

The elution circuit consisted of 8 stages of counter current elution with solvent extraction raffinate. The volume of each cell in the stripping circuit was ~1,5 L.

The resin employed was the used resin left at the end of run 2 and had reduced in volume from 300 mL per stage to approximately 280 mL per stage. There were a total of 20 resin batches in the CIX circuit (adsorption and elution). Both circuits were operated at ambient temperature.

There was one additional standby cell placed adjacent to the adsorption train. The loaded resin (topmost cell in the adsorption train) was separated from the solution by passing through a 350 μm screen and then transferred to the last cell in the elution circuit. Likewise, the fully eluted resin (topmost cell in the elution train) was recovered and placed in the stand-by cell in the extraction circuit. They were then moved up to the next position in the train. The indexing procedure involved some back mixing when the contents of the top most cell in the adsorption and elution trains were drained back into their respective feed tanks while recovering resin. Back mixing required the CIX adsorption and elution feed rate to be increased proportionally. Indexing of resin was typically performed at 1½ to 4 hourly intervals, depending on the uranium flux and resin loading.

Concentrated eluate from the CIX elution circuit was collected in a surge tank mounted on scales. This was then transferred in batches to the SX PLS tank on scales to be fed into the SX circuit. Sulphuric acid concentration in SX raffinate was adjusted to 100 g/L, prior to being fed in batches to the CIX eluant feed tank. Towards the end of the run, sulphuric acid (H2SO4) concentration was increased to 130 g/L. Scrub product solution was batch transferred to the CIX elution stage and fed to elution cell 2, due to the residual uranium tenor. At times during run 3, scrub product was not fed to the elution stage due to high uranium concentrations in the product solution. In these instances scrub product was recycled to the SX PLS tank.

All resins were regenerated between 13 and 15 April 2010. The regeneration process entailed removing the eluted resin after it had been removed (indexed) from the S1 position. The resin was then washed in de-ionised water and placed sequentially in 20 g/L sodium hydroxide (NaOH), 60 g/L NaOH, 20 g/L NaOH, de-ionised water and 2 g/L H2SO4, respectively, for 15 minutes each. Once the regeneration process was complete the resin was placed into the standby position in the CIX extraction circuit and put back into operation once the next index was performed. It took roughly 2½ days to complete the regeneration process on all resins. Each resin was only regenerated once during run 3.

The CIX circuit operated for a total of 326 hours with >97% availability during run 3.

8.3.12 Solvent Extraction

The solvent extraction circuit included four extraction stages, three scrubbing stages and three stripping stages.

All mixer-settlers and after-settlers were constructed from clear PVC with welded joints, rather than glued. All cells were of the same dimension; mixers were 50 mm wide, 50 mm long and 40 mm deep (100 mL live volume) whilst settlers were 50 mm wide, 160 mm long and 50 mm deep (400 mL live volume). After-settlers comprised a mixer box and three compartments with baffled weir arrangements. The settlers housed a heat exchanger to maintain the circuit temperature of ~40°C.

In the mixer boxes organic and aqueous were mixed using slotted disc impellors 30 mm in diameter. Each disc contained 4 slots, 4 mm wide and 5 mm deep, cut across its diameter. The agitators were operated between 1100 to 1300 rpm. All circuits were operated in a counter-current mode, with aqueous and organic from the previous stages being introduced to the mixer under a slotted disc impellor. The impellor operated as a pump mixer, drawing the organic and aqueous into the mixer and the resulting mixture then overflowed a weir into the settler where the phases were disengaged. The organic and aqueous overflowed the settler via individual weirs and advanced to the next stage.

采矿翻译,矿业翻译,矿业合同翻译 采矿技术翻译,矿产翻译案例

 

上一篇:联系地址

下一篇:委托翻译合同书