Chapter 1

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encourage 'seed-bank transfer' of dormant seeds and fresh seeds; and. Ш if topsoil is ..... cross-border flows of capital, investment, manufacturing etc. .... Fish Habitat Design, Operation and Reclamation Workbook and Worksheets for Placer.

THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

Chapter 1

17

Profitable Gold Mining - with Low Impacts

in CHAPTER 1… …we look at how to minimise environmental impacts, at the same time as maximising efficiency to generate higher profits. It may seem odd that LESS impacts = MORE profits, but that is clearly demonstrated throughout the book.

One of many ways to minimise impacts and maximise profits – a fully mobile wash-plant that moves effortlessly on a pond, keeping pace with an excavator that feeds it. No trucks are needed to feed the wash-plant. (sketch: Robin Grayson)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD M INERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

1.1

Maximise Profits

18

Maximise profits

Maximise % gold recovery BAT - recover at least 90% of the gold content: 

  

 





a mine may seem to recover most gold, but a common phenomenon is that the gold resource is actually MUCH MORE, being underestimated by gold lost during drilling; in Mongolia alone, tons of gold are thrown away each year, passing through wash-plants; in Siberia the situation is worse, in Africa and South America just as bad; a remedy is to use a ‘tuned sluice’, whose exact dimensions, slope, feed rate and water flow conform precisely to the findings of research results from across the world; if the gold is tiny (‘fine gold’) use special equipment - jigs, centrifuges, spirals etc; do not make the only priority to MAXIMISE OUTPUT PER DAY, regardless of environmental damage and ignoring how much gold is left behind; the overarching priority is to MAXIMISE OUTPUT PER CUBIC METRE OF ORE, as well as to MAXIMISE OUTPUT PER DAY yet to also MINIMISE IMPACTS; and stiff clay is solved by special equipment such as scrubbers or eco-friendly chemicals.

Eliminate trucking to the wash-plant BAT - NEVER use trucks to transport pay gravel to the wash-plant:    

do not truck the placer ore to the wash-plant!; ELIMINATE TRUCKING OF PAY GRAVEL, with enormous cost savings; choose a wash-plant that is fully mobile and travels to the placer; and mobility is by floating the wash-plant on a pontoon or dredge, or put on skids or wheels.

 BAT - a fully mobile wash-plant, fed by a hydraulic excavator - eliminating trucking pay gravel. (photo: Danny Walker of Cold Gold Mongolia Ltd)

Eliminate double handling of materials BAT - NEVER double-handle topsoil, overburden or pay gravel:  



do not double-handle any material, or see profits slashed and risk bankruptcy; do not SIDECAST materials using trucks, draglines or bulldozers, an expensive luxury:  the footprint of the mine is wastefully wide; and  the cost of DOUBLE-HANDLING to “fill in the pit later” is prohibitive. the overarching priority is to CAST TO THE REAR, to create the final landform by SINGLE-HANDLING of the waste in a single movement - the same day!

Create spreadsheets in EXCEL software BAT - type drilling results in spreadsheets to find Economic Envelope:    

 

do not rely solely on hard-copy reports of gold reserves; recognise the area, thickness and value of reserves fluctuate with the world gold price; assign each line of boreholes a set of columns in an EXCEL sheet; link each column to a master sheet to see if each borehole is ‘IN’ or ‘OUT’ of reserves, the master sheet having variables such as gold price, % gold recovery, royalties etc.; on the EXCEL sheets, choose the Mining Envelope that is profitable and achievable; and using the master sheet, reduce risk by conducting sensitivity analyses, for instance:  gold price forecast - pessimistic, realistic, optimistic;  royalties forecast - high, medium, low; and  gold recovery forecast - 70%, 80%, 90%.

 BAT - coarse, medium and fine gold recovered by an IHC 3-stage 3-cell jig-plant from tailings issuing from a Russian-style flat-bar sluice fed by a water cannon and static screen. (photo: Ms Tsevel Delgertsoo)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

1.2

Minimise Impacts

19

Minimise impacts

Minimum land take BAT - strive to limit the mine’s footprint to the area excavated:      

dump all waste immediately into freshly mined-out areas (‘rear-casting’, ‘backfilling’); if possible, only route plant inside the excavated area; dispense with haul-roads for placer to the wash-plant, by moving the wash-plant; if possible, dispense with haul-roads for overburden by using conveyors; do not dump any waste to the sides (‘side-casting’); and do not store any topsoil but re-spread it immediately on backfilled areas.

BAT - strive to minimise the area being mined at any one time:     

 BAT - rear-casting of materials and covering in topsoil the same day. (photo: Danny Walker of Cold Gold Mongolia Ltd)

dump all waste immediately into freshly mined-out areas (‘rear-casting’, ‘backfilling’); backfill the mined-out area as a continuous non-stop operation without double-handling; wash-plant advances forward to keep pace with the advancing mine face; wash-plant has stacker conveyors and/or slurry pipes to continuously rear-cast waste; cut the footprint (area and volume) needed for pond(s) by:  use a wash-plant with low water consumption per m3 solids washed;  install water recycling pipework inside the wash-plant;  install water recovering devices such as cyclones, pinched sluices, lamella etc.;  design settling ponds carefully for maximum efficiency for minimum footprint;  use flocculants, cyclones or HydrotechTM to further reduce the footprint; and  use a ‘mobile pond’ to advance with the mining face and is backfilled at the rear.

Conserve topsoil or add soil-forming material

 BAT - same view, 2 years after mining. (photo: Robin Grayson)

BAT - re-spread topsoil immediately after topsoil is stripped:     

respread topsoil on back-filled areas the SAME DAY the topsoil is stripped; do not store any topsoil, always re-spread it immediately on backfilled areas; encourage ‘vegetation transfer’ of sods, stumps, tubers, bulbs, suckers; encourage ‘seed-bank transfer’ of dormant seeds and fresh seeds; and if topsoil is too thin or impossible to strip, then focus on adding soil-forming materials.

BAT - always add soil-forming materials:   

recognise that 100% conservation of topsoil cannot be achieved; recognise that re-spread topsoil is prone to deterioration; in mitigation, add soil-forming material:  spread waste fines from the wash-plant over backfill to create soil profiles;  achieve spreading by slurry pipes or as sludge from cyclones;  as a last resort import some topsoil from nearby;  as a last resort, rake in a hay-crop with its seed bank from nearby;  as an alternative, create wetlands (marsh or open water) that do not need topsoil.

 BAT - view on the valley floor of the same locality, 2 years after mining. (photo: Robin Grayson)

Continuous landform creation BAT - create the final landform as a continuous operation:      

dump all waste immediately into freshly mined-out areas (‘rear-casting’, ‘backfilling’); use conveyors, or if unavoidable use trucks, to achieve most of the backfilling; use stacker conveyors to spread washed oversize as a lower carpet of coarse waste; if necessary use a small dozer to achieve the final desired landform; use slurry pipelines and cyclones to spread waste undersize to bury all coarse waste; and spread topsoil (if recoverable) to bury washed undersize using conveyor or by trucks.

 BAT - final landform after rearcasting of materials at Yalbag Mine by Cold Gold Mongolia Ltd. (photo: Battulga of the Minerals Resources Authority of Mongolia MRAM)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

Zero mercury use

20

Minimise impacts

BAT - mercury is strictly prohibited from the mine and all operations:  

do not use mercury for any stage of the gold recovery system; do not tolerate any mercury on the company land, even for experiments.

Minimum water use BAT - water usage is kept as low as possible: 

cut the water consumption by:  use a wash-plant with low water consumption per m3 solids washed;  ensure water recycling inside the wash-plant;  maximise water recycling of effluent (see below);  design settling ponds carefully for maximum efficiency for minimum volume;  minimise evaporation loss by minimising the surface area of pond(s); and  minimise leakage loss by good engineering design, and if necessary add a liner.

Maximum water recycling

 BAT - feather and gentle blowing produce a clean smeltable concentrate of gold! More than 11 tons of placer gold a year is cleaned by feather in Mongolia without mercury. (photo: Enkhbold Sumiya)

BAT - water recycling is seen as profitable not just desirable:  

   

recycling water is environmentally desirable; recycling water cuts costs and increases profits:  reduce water consumption = lower water use fees;  gold production possible even in a moderate drought;  reduced cost of pumping water from a distant source;  less engineering work to create/maintain water settling ponds;  less engineering work to create/maintain water storage pond; and  less water stored on site = less risk of uncontrolled discharge and penalties. install water recovering devices such as cyclones, pinched sluices, lamella etc.; ensure the wash-plant can re-use somewhat ‘dirty’ water; recycling water inside a wash-plant is the best type of recycling; recycling effluent from the wash-plant is achieved by:  install water recovering devices such as cyclones, pinched sluices, lamella etc.;  ensure the wash-plant can re-use somewhat ‘dirty’ water;  design settling ponds carefully to produce water ‘clean enough’ for recycling; and  use flocculants, cyclones or HydrotechTM system to further clean the water.

 BAT - Cleangold sluice traps gold in corduroy-like ridges of fluidised magnetite. (photo: Robin Grayson)

Zero effluent discharge BAT - zero effluent discharge is seen as essential not just desirable:  



zero effluent discharge is environmentally desirable; zero effluent discharge minimises many costs:  pumping costs for replenishment of water supply;  fees for water usage (less water is used);  fees for effluent discharge (no effluent is discharged);  penalties for emissions etc.;  complaints from anglers and other water users; and  liabilities from water users downstream . zero effluent discharge is technically feasible at affordable cost.

 BAT - Wilfley shaking table recovering gold without using mercury. (photo: Chris Temulliensen)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD M INERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

1.3

Maximise Benefits

21

Maximise benefits

Wildlife gain… BAT - wildlife gain is seen as routine not as something special: 



recognise all mining, especially placer gold mining, is destructive of wildlife, therefore:  conduct wildlife surveys before, during and after mining;  seize opportunities for wildlife gain, such as: - wetlands - marshes, swamps and ponds; - hydroseres - transition between open water and marshland; - sand cliffs - used by some birds, reptiles and insects; - islands - safe nesting/roost sites away from humans and predators; - forest margins - often with high biodiversity; and - species recovery - habitat creation/manipulation to favour ‘flagship’ species.  consider creating a temporary nature reserve during mining operations; or  consider funding a permanent nature reserve as part of mine closure planning. if long-term wildlife gain is achieved, the mining is viewed as sustainable.

 BAT - unplanned wildlife gain; new water for Swallowtails in Mongolia. (photo: Robin Grayson)

Pasture gain… BAT - pasture improvement should be considered: 





recognise placer gold often occurs beneath valley pastures important for local herders and even for large-scale commercial livestock rearing (e.g. New Zealand); recognise placer gold mining involves net land-raising and remodelling of landforms, giving opportunities to improve quality and drainage of pasture in some regions; and if long-term pasture improvement is achieved, the mining is viewed as sustainable.

Local economy gain… BAT - often the local economy is driven by placer gold mining:          

enact regulations to ensure local employment in placer gold mines and their suppliers; allocate areas for labour-intensive small-scale placer gold mining for locals; allocate areas for recreational miners to stimulate current/future tourism; encourage placer gold mining as a pathfinder for hard-rock gold mining; stimulate synergy between placer mining and all other forms of mining; stimulate synergy between placer mining and the construction sector; stimulate synergy between placer mining and local commercial banks; create mechanism to ensure diversification and viability of post-mining economy; placer gold mining can easily achieve short-term local economic gain; and if long-term local economic gain is evident, the mining is viewed as sustainable.

 BAT - cyclones spread fines as soil-making material to trigger revegetation. (drawing: Robin Grayson)

National economy gain… BAT - sometimes the national economy benefits from placer gold mining:      

placer gold production often boosts exports; placer gold mines can be a large source of government revenue (e.g. royalties); placer gold output can boost gold reserves of central banks, strengthening currencies; commercial banks strengthened by profitable lending to placer gold miners; some cities are boosted by employment and services from placer gold mines; and if miners’ cash helps diversify the economy, the mining is viewed as sustainable.

 BAT - S100 bucket-wheel excavator strips 200-500m3 of overburden an hour and feeds it to a conveyor. (photo: courtesy of the manufacturer, ThyssenKrupp Fordertechnik - www.tk-mining.com)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

Maximise Benefits - Gold Dredging

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Maximise benefits of gold dredging

Wetlands gain… BAT - strive to enhance the ecological value of wetlands:           

create completely new wetlands of high ecological value; enhance the long-term viability of existing wetlands, reversing natural silting; restore the flood-storage role of degraded floodplains; seek to create more areas of wetlands as a scarce natural resource; do not reduce the sinuosity of stream channels; do not canalise stream channels (avoid deepening or straightening them); do not damage/destroy sensitive fish habitats (e.g. spawning beds); do not cause turbidity downstream; do not cause silting downstream or erosion upstream; wherever possible, dredge beneath floodplains not beneath stream beds; and if long-term wetland increase is achieved, then the dredging is viewed as sustainable.

Land-raising…

 BAT - by adding a hydrocyclone system to the rear stacker conveyor of a bucket-line dredge, the problematic gravely oversize is buried in soil-forming material to trigger revegetation with a high degree of naturalness. (drawing: Robin Grayson)

BAT - combat land-raising to ensure wetlands are maintained:      

recognise placer mining is unusual in ALWAYS resulting in net land-raising; therefore all wetlands are threatened by shallowing or drying out by land-raising; so do not allow uniform land-raising, but side-cast some material; do not damage active floodplains by such sidecasting; consider sidecasting material via slurry pipes onto inactive floodplains (‘terraces’); and consider creating islands of material that otherwise destroy wetlands by landraising.

Topsoil replacement… BAT - create large volumes of soil-forming materials:    

gold dredging creates large volumes of soil-forming materials, by separating the fines; respreading fines stimulates rapid revegetation by shrubs and trees; the resulting woods have primary forest characteristics - high naturalness; and original topsoil can be discarded if new areas of open water do not need such material.

Channel restoration… BAT - avoid dredging channels, or restore them with care:       

wherever possible, dredge beneath floodplains not beneath stream beds; do not reduce the sinuosity of stream channels; do not canalise stream channels (avoid deepening or straightening them); do not damage/destroy sensitive fish habitats (e.g. spawning beds); do not cause turbidity downstream; do not cause silting downstream or erosion upstream; and if channel integrity and functionality are kept, the dredging is viewed as sustainable.

 BAT - by stripping the overburden by using an IHC cutter-suction dredge, the area of wetlands can be enlarged and the overburden settled at a distance on terraces. (drawing: Robin Grayson)



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THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

1.4

Rehabilitate Every Hour, Every Day

Continuous rehabilitation

Rehabilitation is a daily routine… BAT - rehabilitation is part of the daily routine of the mining operation:         

the new landform and its vegetation cover is created bit-by-bit, every day; doing this ensures single handling of materials, therefore lower costs; doing this ensures minimum land take as no storage dumps; rehabilitation is seen as part of mining, not as something for ‘later’; much reduced risk of mine-site being abandoned in a derelict state; much higher standard of re-vegetation possible, as earthmoving equipment is available; company reputation becomes linked to its willingness to undertake daily rehabilitation; encourages mobile wash-plant and mobile tailings pond, minimising impacts; and is usually more efficient and more profitable than post-mining rehabilitation.

 BAT - the minimum footprint of a large placer gold mine at Aruhura in New Zealand. (photo: courtesy of L&M Mining Ltd of New Zealand)

Not in phases at end of blocks… 



mining a block and then rehabilitating the block before commencing on the next block is traditionally viewed as ‘best practice’ but tends to encourage excessive mine footprint, double handling of overburden, damage to topsoil during storage, and excessive use of trucks and bulldozers, therefore it is rejected as BAT by this author; and ‘phased’ means at the end of mining there is a risk of the final block being left derelict.

3

1

2

4

Not delayed until the end of mining… 



waiting until placer mining has ceased risks the company disappearing, or de-motivated to rehabilitate the abandoned mine-site. This is the global picture, especially for small to medium-sized placer gold mines; and mine managers conclude rehabilitation agreements, but after mining the company may no longer be in the mining sector, or disinterested in rehabilitation as it is deemed an “extra” cost at a time when the company no longer has cash flow from the mine.

 BAT - close-up of the Aruhura Mine showing continuous rehabilitation being implemented 1: levelling of dumped overburden; 2: dumping of topsoil; 3: spreading of topsoil; 4: re-vegetating of site. (photo: interpretation by Robin Grayson of photo courtesy of L&M Mining Ltd of New Zealand)

4

1

BAT - the tiny footprint of a placer gold mine in New Zealand, rehabilitating in the foreground. (photo: courtesy of West Coast Regional Council of New Zealand)

2

3

 BAT - a different block of the Aruhura Mine again showing continuous rehabilitation underway 1: levelling of dumped overburden; 2: dumping of topsoil; 3: spreading of topsoil; 4: re-vegetating of site. (photo: interpretation by Robin Grayson of photo courtesy of L&M Mining Ltd of New Zealand)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD M INERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

1.5

BAT - More Profit with Less Impact

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Best Available Techniques - BAT

BAT means ‘Best Available Techniques’ Best Available Techniques (BAT) are: “the most effective and advanced stage in the development of activities and their methods of operation which indicates the practicable suitability of particular techniques for providing the basis for emission limit values designed to prevent, and where that is not practicable, generally to reduce the emissions and the impact on the environment as a whole.” - as defined in the European Union’s EC Directive 96/61. The wording implies that BAT encompasses not only the technology, but also: 



the manner in which the installation is operated, to ensure a high level of environmental protection as a whole; and balances the financial costs and environmental benefits. Indeed BAT has sometimes been termed BATNEEC - “best available techniques not entailing excessive cost.”

Definition of ‘Best’ Best means, in relation to techniques, the most effective in achieving a high general level of protection of the environment as a whole.

 BAT - for recovering fine gold - LEFT - Reichert spirals, RIGHT - Reichert cones. (photo left: Willem Kramer - www.adms.nl; photo right: Roche Mining - www.rochemt.com.au)

Definition of ‘Available’ Available means, in relation to techniques, those developed on a scale which allows implementation in the relevant industrial sector, under economically and technically viable conditions, taking into consideration the cost and advantages - regardless of if the techniques are used or produced inside the operator’s country so long as they are reasonably accessible.

Definition of ‘Techniques’ Techniques include both the technology used and the way in which the installation is designed, built, maintained, operated and decommissioned.

BAT and BATNEEC BAT is implicitly BATNEEC - ‘Best Available Techniques Not Exceeding Excessive Cost’. BATNEEC addresses financial concerns. But this pays no regard to type of business entity.

BAT or BATTE? BAT needs to be BATTE - ‘Best Available Techniques Tailored for Entities’, meaning pitched to the type of entity. The term BATTE is coined here to emphasise that the BAT concept can be extended from companies to encompass entities of very different motivation, management, organisation and behaviour such as artisanal miners and recreational miners. The Gold Book strives for BATTE: BAT-CO tailored for formal mining companies - many chapters in this Manual; BAT-ASM tailored for artisanal and small scale miners - several chapters; and BAT-RM tailored for recreational miners - no chapters, but implicit throughout.

 BAT - for recovering very fine gold - LEFT - Kelsey centrifugal jig, RIGHT - GemeniTM table. (photos: courtesy of Dale Henderson of Roche Mining - www.rochemt.com.au)

 BAT - recovering fine to coarse gold - unbacked NomadTM matting. (image: Robin Grayson)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

BAT nationally, internationally and globally

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Best Available Techniques - BAT

BAT selection at national level BAT may be selected at national level. This ensures local context - legislative, regulatory, environmental, climatic, social, cultural and economic - but is doomed to be skewed towards favouring techniques already in use in that country and biased by the strengths/weaknesses of national equipment manufacturers. The risk is high of creating a BAT that is not the BEST, and risks stifling the inventiveness and competitiveness essential for BAT to evolve. For instance, “BAT dinosaurs” are a lamentable feature of the placer mining equipment industry of the former soviet bloc, still largely dictated by the mandatory GOST standards. BATs for small sectors, such as placer gold mining, cannot be realistically designed at national level, as there is rarely enough expertise in any single country to arrive at a robust BAT that is capable of evolving and maintaining its effectiveness for more than a few years.

BAT selection at international level BAT are better if selected at international level. This still allows some local context - such as across the member states of the European Union now connected by convergent environmental legal frameworks, technical standards and cross-border flows of capital, investment, manufacturing etc. At international level in Western Europe, a single set of BAT Reference Documents (BREFs) is being created for the EU Member States by the European Integration Pollution Prevention and Control Bureau (EIPPCB). A BREF presents consensus between all EU member states. Due to the virtual extinction of placer mining in the European Union, there is no BREF on placer gold, but the BREFs do give guidance on how to select BAT for any situation.

 BAT - Rohr grab dredge, capable of mining to great depths underwater. (photo: courtesy of Joachim Rohr of Rohr Corp - www.rohrcorp.com)

BAT selection at global level BAT for small sectors are best if global. This is desirable as small sectors are often too fragmented globally for any single region to be expected to already have a full set of BAT. In this regard, placer gold mining is an extreme example of geographical and technological fragmentation. But there is no agreed global mechanism for gathering and assessing techniques from around the world to arrive at a global BAT. Some organisation should take the lead, such as the World Bank, International Finance Corporation (IFC), United Nations Development Programme (UNDP) or United Nations Industrial Development Organisation (UNIDO), but there is no sign of any of them doing so. To address this vacuum, the author has taken the initiative and searched globally for ‘fragments of excellence’ and endeavoured to pull them together into a coherent Global BAT for placer gold mining.  BAT - IHC wheel dredge, ideal for mining placer as slurry, piped to a floating wash-plant for gold recovery. (sketch: Robin Grayson based on materials from IHC Holland NV - www.ihcholland.com)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD MINERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

BAT for ‘Best Available Techniques’

26

Best Available Techniques - BAT

Operational factors Operational advantages:       

low cost to operate and update; reduces risk to the environment; reduces risk to miners, investors, banks and regulators; cuts need for government regulation and enforcement; encourages global competition between regionally-based equipment manufacturers; encourages and enables rapid technology transfer globally; and encourages research institutes and inventors to think and act globally.

Operational disadvantages:    

difficult to initiate; risk of distortion by equipment manufacturers protecting their markets; risk of distortion by specialists resistant to change; and risk of distortion by governments protecting ‘national interests’.

 BAT - mobile wash-plant with hydraulic riffled sluices, plus cyclones to stimulate soil formation. (drawing: Robin Grayson)

Environmental factors       

risk to topsoil resource: significantly reduced. risk to mineral resource: significantly reduced. risk of dust generation: significantly reduced. risk of sheet runoff and effluent discharges: significantly reduced. risk to surface waters: significantly reduced. risk to biodiversity: significantly reduced. risk of poor land reclamation: significantly reduced.

Key factors for BAT determination:  

all impacts minimised; and enforcement and regulation minimised.

 BAT - same wash-plant on a pontoon, again plus cyclones to stimulate soil formation. (drawing: Robin Grayson)

BAT conclusion Best Available Techniques are:  top priority for placer gold mining

Financial incentives for introducing BAT It is recommended that: 



governments should introduce substantial financial incentives for placer mine proposals that realistically attempt to implement BAT. Incentives are justified because:  environmental impacts are minimised;  gold recovery maximised, (increasing Government income from royalties and taxes);  export earnings are increased;  risk of uncontrolled informal mining is reduced (little gold left behind);  government costs of enforcement are minimised; and  ‘demonstration effect’ is shown to other investors and miners. incentives for BAT should be open to local as well as foreign investors because:  local companies are often capable of using BAT, but require incentives to do so; and  local companies often predominate in placer mining.

 ALMOST BAT - wash-plant with hydraulic riffled sluices on a pontoon, but lacking cyclones. (photo: West Coast Regional Council of New Zealand)

 BAT - wash-plant with IHC 2-stage Jig Plant on a pontoon, plus cyclones to stimulate soil formation. (drawing: Robin Grayson)



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD M INERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

Chapter 1

27

GOLD PAGES

Best Available Techniques for Placer Gold Mining 1.

Ackels, Del; and James Madonna (1985). Placer Mining in Alaska with IHC jigs. Alaskan Prospectors and Miners News. Fall Edition, 9 pages. $7.95. Order hardcopy: www.alaskagoldinformationcenter.com/GoldInfo.html

2.

Ackels, Del (1985). Placer mining in Alaska with IHC jigs. IHC Holland.

3.

Ackels, Del (1985). Some aspects of gold recovery with IHC jigs. Pages 86-99 in: James A. Madonna (editor and compiler) Proceedings of the 7th Annual Conference on Alaskan Placer Mining. Held 28-29th March 1985 in Fairbanks, Alaska. Alaska Prospectors Publication Company.

4.

Ackles, Gail (2006). Gold is where you find it. Authorhouse, 116 pages.

5.

Anon (2010). Yukon Mineral and Coal Exploration - Best Management Practices and Regulatory Guide. Yukon Chamber of Mines, 198 pages. Download PDF: www.yukonminers.ca/Libraries/Documents/BMP_RG_October28_FINAL_WebFile.sflb.ashx

6.

Anon (2010). Yukon Placer Mining - Best Management Practices for Heritage Resources. Heritage Resources - Cultural Services Branch, Tourism & Culture, Yukon Government, 1st edition, 18 pages. Download PDF: www.emr.gov.yk.ca/mining/pdf/placer_mining_bmp.pdf Anon (2010). Fish Habitat Design, Operation and Reclamation Workbook and Worksheets for Placer Mining in the Yukon Territory. Version 1.3. Yukon Placer Secretariat, 113 pages. Download PDF: www.yukonplacersecretariat.ca/pdf/Workbook__revisions_10_nov_1.pdf

13.

ESSENTIAL READING - high % gold recovery using semi-mobile IHC jigs at Gold Dust Creek in Alaska.

The Yukon Award scheme commenced in 1999, and the 1999 winner was Tic Exploration Ltd for its Gladstone Creek Mine, that uses 2 floating wash-plants of NZ type, with trommels feeding hydraulic riffles over Nomad matting. Rehabilitation is continuous with the mining and the dredge ponds are reclaimed on an annual basis. The 2000 winner was Grew Creek Ventures Ltd’s Hunker Creek Mine for clearing up debris from previous miners, contouring the tailings to a gentle topography and spreading black muck over the tailings to promote rapid re-vegetation, as well as establishing a wide stable stream channel and small ponds to enhance local wildlife. A Special ‘Long-Time Achievement in Mine Reclamation’ award was made in 2001 to Norman Ross of Ross Mining Ltd, with recognition of that company’s annual reclamation since the early 1980s of the Dominion Creek Mine, creating a landscape of rolling hills, small lakes and stable and productive streams, with the wetlands favoured by migratory wildlife and moose use the willow-rich area to calve each year. The 2001 winner was T.D. Oilfield Services Ltd’ Hunker Creek Mine for rehabilitation to a ‘better than natural’ landscape incorporating extensive new wetlands and grasslands, and the same company was again winner in 2002 for restoration of the river bank of the Indian River as part of a continuous reclamation programme in which tailings mounds are completely flattened and overburden spread evenly over the whole area.

Reprint of the article on high % gold recovery using semi-mobile IHC jigs at Gold Dust Creek in Alaska.

Summary account of high % gold recovery using semi-mobile IHC jigs at Gold Dust Creek in Alaska.

7.

Includes an account of the effective use of innovative IHC jigs at Gold Dust Creek in Alaska.

8.

Grayson, Robin; and Gerrit Bazuin (2003). Low-cost placer gold mining using fully mobile wash-plants. [ABSTRACT] World Placer Journal volume 3. Download PDF: www.mine.mn/WPJ3_2_Cutting_Costs_in_placer_gold_mining.pdf

9.

Grayson, Robin (2004). Progress towards a global BAT for placer gold mining. World Placer Journal, volume 4 [ABSTRACT] Read at: www.mine.mn/WPJ4_0_World_Placer_Journal.htm

10.

Grayson, Robin (2007). Fine Gold Recovery - alternatives to Mercury and Cyanide. World Placer Journal, volume 7, pages 67-162. Download set of 75 PDFs: www.mine.mn/Robin_Grayson_gold_recovery.htm

14.

ESSENTIAL READING - An in-depth review of the gravitational devices used to recover gold, particularly fine gold. A study of many hundreds of patents and devices, some new many long-forgotten, suggests that cheap home-made gravitational devices can now defeat mercury and some even challenge cyanide leaching of extremely fine gold.

11.

Nordin, K.A. (2010). Guidebook of Mitigation Measures for Placer Mining in the Yukon. Laberge Environmental Services for Yukon Placer Secretariat, 132 pages. Download PDF: www.yukonplacersecretariat.ca/pdf/Guidebook_Nov_1_2010.pdf

15.

Walker, Danny (2001). Placer Gold Mining in Mongolia - the New Zealand Way. World Placer Journal, volume 2. Download PDF: www.mine.mn/WPJ2_3_NZ_mobile_mining

16.

YEDA (1993). Placer Gold Dredging using an Excavator and a Floating Processing Plant. Authors: Forty Mile Placers Inc, Yukon. Indian and Northern Affairs Canada. Northern Affairs: Yukon Open File 1993-2 (T). 53 pages. Funded by the Canada/Yukon Economic Development Agreement (YEDA). Download PDF: www.geology.gov.yk.ca

ESSENTIAL READING - the clearest detailed account of placer gold mining using a fully mobile wash-plant with hydraulic riffled sluices, achieving high % gold recovery and SAME-DAY rehabilitation of topsoil.

Brief conceptual account of how adopting Best Available Techniques (BAT) can minimise impacts and increase profits.

Brief progress report on applying the BAT concept to placer gold mining on a global basis.

Mining Inspection Division (2003). Robert E Leikie Award for Outstanding Reclamation Practices. Pages 17-22 in: Yukon Placer Industry 1998-2002. Mineral Resources Directorate, Yukon Region, Indian and Northern Affairs Canada, 214 pages. Download PDF: www.geology.gov.yk.ca

ESSENTIAL READING - fully detailed account of using a pontoon-based floating New Zealand wash-plant (trommel, hydraulic riffles and rear stacker conveyor), fed by a land-based hydraulic excavator, cutting operational costs and mimimising impact.

17.

YEDA (1995). Testing the Viability of Floater Dredging in Frozen Ground. Authors: Forty Mile Placers Inc, Yukon. Indian and Northern Affairs Canada. Northern Affairs: Yukon Open File 1995-2 (T). 25 pages. Funded by the Canada/Yukon Economic Development Agreement (YEDA). Download PDF: www.geology.gov.yk.ca

ESSENTIAL READING - fully detailed account of how to flood frozen gravel to defrost it, and how to mine it using a pontoon-based floating New Zealand wash-plant (trommel, hydraulic riffles and rear stacker conveyor), fed by a land-based hydraulic excavator, cutting operational costs and mimimising impact.

Grayson, Robin; and Chimed-Erdene Baatar (2007). Satellite monitoring of placer gold mining reveal Worst Available Techniques (WAT) widespread in Mongolia, China and Russian Federation with large avoidable impacts. Proceedings of the 2nd National Workshop on Remote Sensing/GIS for Mongolian Environment, pages 38-47. Demonstration of the value of low-cost remote sensing, as typified by Google Earth satellite imagery, in monitoring the current activity of placer gold dredges in Siberia, Mongolia and NE China, as well as the natural revegetation of gold dredge tailings in Alaska, California and elsewhere, and its successful rehabilitation to farmland in Australia.

12.

Manhire; and Loudon (in preparation). L&M Mining Limited; large scale alluvial gold mining operations in Otago, Southland and Westland between 1987 and 2002. Australasian Institute of Mining and Metallurgy AusIMM Monograph (in preparation).

ESSENTIAL READING - presents the only examples known to the author of BAT in action for very large placer gold mines.



THE GOLD MINERS BOOK - BEST AVAILABLE TECHNIQUES FOR PLACER GOLD M INERS – COPYRIGHT 2015, 2016, 2017: AUTHOR: R OBIN GRAYSON

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Best Available Techniques - BAT

BEST AVAILABLE TECHNIQUES - Arahura Placer Mine of L&M - NEW ZEALAND (photo: courtesy of L&M)