Rasp Mine
Zinc – Lead – Silver Project
Project Approval No. 07-0018
January 2011
Waste Management Plan V2
April 2012

DISTRIBUTION: CONTROLLED

REV / DATE / REVISION / PREPARED / REVIEWED / APPROVED
SCOPE/PURPOSE / INIT / SIGN / INIT / SIGN / INIT / SIGN
1 / 30/3/2012 / Original / PB / Peter Boyle (ENVIRON) / BB / Brendan Barker / BB / Brendan Barker
2 / 26/4/2012 / Updated for TSF2 and incident reporting, removal of use of septic tank and salt recovery investigations and other minor modifications / GW / Gwen Wilson / BJ / Ben Jones / TD / Tony Davis
Document Owner / Environment & Community Officer / Signature / Ben Jones / Department / SHE / Date / Apr 2012

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ContentsPage

1Purpose

2Scope

3Context

4Objectives

5Performance Targets

6Mine Waste Streams

7Legal Obligations

8Waste Generated and Management

9Application of the Waste Hierarchy

10Control Measures

List of Tables

Table 1: Project Approval Conditions for Waste Management

Table 2: Waste Rock & Tailings Disposal

Table3: Predicted Annual Tailings Volumes and TSF2 Filling Data

Table 4: Non-Mineral Waste Types and Management

Table 5:Waste Facility (Onsite and Offsite) Audits and Inspections

Table 6: Responsibilities

List of Figures

Figure 1: Waste Management Hierarchy

Figure 2: TSF2 Blackwood Pit Looking East

Figure 3: Layout of the Delivery and Return Lines at Blackwood Pit

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1Purpose

1.1This Waste Management Plan (WMP) outlines the wastes generated by the Rasp Mine operations and details requirements for storage and disposal.

2Scope

2.1This WMP applies to any waste generated by employees, contractors and processes at the Rasp Mine located on Consolidated Mine Lease 7 (CML7) in Broken Hill.

3Context

3.1BHOP proposes to mine the Western Mineralisation and Centenary Mineralisation and Main Lode Pillars, zinc-lead-silver masses within the Project Area. Mining will take place over 15 years including one year to construct the processing plant, one year to complete closure activities and an estimated 13 years for extraction of ore from underground mining, at a maximum rate of 750,000tpa and produce zinc (87,000 t) and lead (44,000 t) concentrates. The concentrates will be despatched by rail to the CBH Resources Ltd owned ship loader (ConPorts Pty Ltd) at Newcastle.

4Objectives

4.1Waste management is inclusive of the generation of waste through to collection, transport, treatment, recycling/reuse, final use or disposal and where applicable, the supervision and maintenance of final waste facilities.

4.2The objectives of this WMP are:

  • To minimise waste generation at source;
  • To maximise reuse and recycling of waste products in a safe effective manner;
  • To minimise the adverse effects of waste disposal on the local and regional environment ensuring that pollution of air, land and water are prevented; and
  • To comply with legislative requirements and endeavour to meet best practice industry standards and waste disposal guidelines.
  • To identify potential re-use or recycling opportunities and ensure appropriate handling and collection procedures are in place.
  • To investigate methods to minimise waste generated by the mine and implement reasonable and feasible measures to minimise waste.

5Performance Targets

5.1All storage and disposal waste to be in accordance with relevant Australian Standards.

5.2To recycle and reuse waste products wherever economical feasible and practicable.

5.3To achieve 60% total recycling of non-mineral waste.

6Mine Waste Streams

6.1The wastes that the Mine will generate can be categorised as mineral and non-mineral wastes.

6.2Mineral wastes generated by the mine consist of:

  • waste rock comprised of inert aluminosilicate minerals such as feldspar, quartz, biotite, muscovite and sillimanite
  • waste stream from ore processing (tailings).
  • Non-mineral wastes include:
  • general domestic-type wastes from the on-site buildings and routine maintenance consumables;
  • fencing materials;
  • oils and grease; and
  • sewerage.

7Legal Obligations

7.1Project Approval was granted by the Department of Planning and Infrastructure (DoPI) in January 2011. Conditions of this Approval are outlined in Table 1 together with the relevant section(s) within this document where the Condition is addressed.

Table 1: Project Approval Conditions for Waste Management

Obligations / Section of the WMP
Condition 32: The Proponent shall:
(a) Minimize the waste generated by the project; and (b) ensure that the waste generated by the project is appropriately stored, handled, and disposed of, to the satisfaction of the Director-General.
Condition 33: The Proponent shall prepare and implement a Waste Management Plan for the project to the satisfaction of the Director-General. This plan must:
(a) identify the various waste streams of the project; / Whole of document
Section 8 Waste Generated and Management
(b) estimate the volumes of tailings and other waste material that would be generated by the project; / Section 8.3Tailing Disposal
(c) describe and justify the proposed strategy for disposing of this waste material; / Section 8.3 Tailings Disposal
d) describe what measures would be implemented to meet the requirements set out above in condition 32; and / Section 8.3 and Section 10 Control Measures
(e) include a program to monitor the effectiveness of these measures. / Section 10.3 Monitoring, Section 10.4 Facility Inspections and Audits, Section 10.6 Reporting of Performance and Section 10.8 Management Review
“2. The Proponent shall ensure that the management plans required under this approval are prepared in accordance with relevant guidelines, and include:
(a) detailed baseline data; / Section 7 Legal Obligations
Section 8 Waste Generated and Management
(b) a description of:
- the relevant statutory requirements (including any relevant approval, licence or lease
conditions);
- any relevant limits or performance measures/criteria; and
- the specific performance indicators that are proposed to be used to judge the performance of,
or guide the implementation of, the project or any management measures; / Section 7 Legal Obligations
Section10.3 Monitoring,Section10.4 Facility Inspections and Audits
Section 10.6 Reporting of Performance
(c) a description of the measures that would be implemented to comply with the relevant statutory requirements, limits, or performance measures/criteria; / Section 8 Waste Generated and Management and Section 10 Control Measures
(d) a program to monitor and report on the:
- impacts and environmental performance of the project; and
- effectiveness of any management measures (see (c) above); / Section 10.3 Monitoring, Section 10.6 Reporting of Performance and Section 10.8 Management Review
(e) a contingency plan to manage any unpredicted impacts and their consequences; / Section 8.3 Tailing disposal and 10.5 Incident Report and Corrective Action
(f) a program to investigate and implement ways to improve the environmental performance of the project over time; / Section10.3 Monitoring,Section10.4 Facility Inspections and Audits, Section 10.6 Reporting of Performance and10.8 Management Review
(g) a protocol for managing and reporting any:
- incidents;
- complaints;
- non-compliances with the conditions of this approval and statutory requirements; and
- exceedances of the impact assessment criteria and/or performance criteria; and /
Section 10.5 Incident Report and Corrective Action and Section 10.6 Reporting of Performance
(h) a protocol for periodic review of the plan. / Section 10.8 Management Review

7.2The Director General Requirements (March 2009) referenced the following policies and guidelines with respect to waste management:

  • Environmental Guidelines: Assessment, classification and management of liquid and non-liquid wastes (EPA 1999).
  • Environmental Guidelines: use of effluent by irrigation (DEC, 2004).
  • Protection of the Environment Operations Act 1997 (POEO Act)
  • Waste Avoidance and Resource Recovery Act 2001.
  • Protection of the Environment Operations (Waste) Regulation 2005
  • Waste Avoidance and Resource Recovery (WARR) Act 2001
  • Environmental Protection Licence – NSW Department of Environment and Conservation
  • The WMP provides a framework to minimise the environment, safety and health hazards associated with the handling, storage and disposal of those waste products generated by activities conducted by or on behalf of BHOP.
  • Protection of the Environment Operations Act 1997

7.4.1BHOP will ensure that the mine will comply with the requirements of the POEO Act, through the adoption of a waste hierarchy philosophy of Avoid, Reuse, Recycle and Disposal.

Figure 1: Waste Management Hierarchy

7.5Waste Avoidance and Resource Recovery (WARR) Act 2001

7.5.1The object of the Act is to encourage the most efficient use of resources, to reduce environmental harm, and to provide for the continual reduction in waste generation.

7.6The production of non-mineral waste will be controlled and reduced through the accurate ordering of materials and the avoidance of over-ordering and potential wastage of materials. All materials, which are available for recycling, will be collected and recycled off-site. Only materials, which do not fit into the above categories, will be disposed of to an appropriately licensed facility.

7.7BHOP will investigate the use of grey water from the site office, bathhouse and other amenities for re-use around the mine site.

7.8BHOP will undertake waste management on site in accordance with the legislation and guidelines listed in section 1.3. All contractors removing waste from site will be suitably licensed with appropriate governing bodies as required. Wastes, which are required to be tracked, will be done so, in accordance with the relevant legislation.

8Waste Generated and Management

8.1Ore excavated during mining operations is processed by an on-site crushing and flotation plant designed to produce high quality lead and zinc concentrates, which will be dispatched by rail to Newcastle for shipping to market. The major wastes produced during mining and mineral processing are waste rock and tailing information. Table 2 provides a summary for their disposal.

Table 2:Waste Rock & Tailings Disposal
Component / Proposed
Waste rock disposal / Underground: Backfill and rehabilitation at closure
Surface: Inert rock material to be used for road repair,bunding and rehabilitation at closure.
Tailings disposal / Tailings will be disposed as backfill underground and in a storage facility. As underground voids become available the spilt will build to approximately 50% underground and 50% disposed in TSF2.

8.2Waste rock

8.2.1Waste characterisation - Waste rock comprises inert aluminosilicate minerals such as feldspar, quartz, biotite, muscovite and sillimanite. These rock types do not generate acidic water; feldspar and sillimanite decomposition consumes acid. A long history of mining in the area supports the approach of no waste rock with acid forming potential. The Potosi Gneiss unit is quarried as ‘blue metal’ for the local Broken Hill market and surrounding areas in the adjacent quarry owned and operated by E B Mawsons & Sons Pty Ltd.

8.2.2On average 300,000 t of waste rockwill be generated annually.

8.2.3Waste rock is predominantly used for backfill, road base, a cover to minimise dust generation and noise bunding. Waste rock from underground mining will be deposited in underground voids as they become available. Where there are no voids available the waste rock is stored in Kintore Pit awaiting back-loading into underground voids upon availability or placed in underground drives waiting for a void to become available.

Inert waste rock, following testing and classification will be utilised as:

  • road base for the construction of underground and surface roads;
  • fill material for earth bunding to be built as part of the noise mitigation; and / or
  • material for rehabilitation purposes on-site.
  • Tailing Disposal

8.3.1It was originally planned to commence tailing deposition by placing tailing in TSF1, which required two additional lifts to an existing tailings storage facility (the All Nations Tailings Storage Facility). As TSF1 was filled tailing would be deposited in TSF2, Blackwood Pit. This was proposed to allow recovery ofthe rich zinc ore at the base of the Blackwood Pit prior to depositing tailings in this facility. Mining engineering investigations concluded that it was not possible to safely remove this material as the structural integrity of a section of the western side of the Pit is poor.

It has been determined that TSF1 will no longer be considered for tailing disposal.

An estimated 6.55Mdryt of tailings will be generated from the Project.

Predictions for tailing generation for the first 9 years of mine life is presented inTable 3. If storage is required above 308.5 mRL, an engineered bund wall would be required near the eastern end of the Pit on the northern side.

Table3: Predicted Annual Tailings Volumes and TSF2 Filling Data

Year / Estimated Surface Tailings Volume
(m3) / Cumulative Tailings Volume
(m3) / Predicted Storage Elevation
(RL m)
1 / 270 698 / 270 698 / 275.0
2 / 234 981 / 505 679 / 281.2
3 / 246 111 / 751 790 / 286.3
4 / 242 293 / 994 083 / 290.7
5 / 256 717 / 1 250 800 / 294.9
6 / 217 263 / 1 468 063 / 298.2
7 / 177 808 / 1 645 871 / 300.6
8 / 168 899 / 1 814 771 / 302.8
9 / 170 596 / 1 985 367 / 304.9

8.3.2Waste characterisation - Preliminary testwork and mass balance calculations indicate that the tailings contain the following elements; zinc (0.4%), lead (0.4%), silver (8 parts per million (ppm)), iron (3.3%), sulphur (1.2%), arsenic (460ppm), bismuth (70ppm), cadmium (trace) and antimony (45ppm).

8.3.3Tailings properties have been defined through test work and from historic mining operations on the site. The tailings properties are:

  • water/solids ratio - 50% solids (after thickening);
  • water/solids ratio - 55% to 60% solids (at point of discharge from back fill plant);
  • 80 tph (average solids only), 40 tph to TSF, 40 tph to underground;
  • 80 tph (liquid only);
  • 62 m3/h volumetric flow;
  • 80% passing 200 micro-metres (after desliming);
  • dry settled density for TSF2 ranges from 1.50 to 1.65 t/m3

8.3.4Tailing Management–Tailings will be directed underground via boreholes and fill lines to mined voids (for use as back fill) and placed backfill underground and in a storage facility. As underground voids become available the spilt will build to approximately 50% underground and 50% disposed in TSF2.Over the life of the mine approximately fifty percent of tailings and fifty percent will be deposited inTSF2 Blackwood Pit, a disused mine pit.


Figure 2: TSF2 Blackwood Pit Looking East

Tailings are piped from the processing plant to the mine backfill plant; pipes are trenched and / or bunded. At the back fill plant the tailings are thickened and separated by cycloning to produce two waste streams differentiated by particle size. The coarser fraction of the tailings stream are directed underground via boreholes and fill lines to mined voids (for use as backfill). The remainder are deposited in surface storage in TSF2 the disused Blackwood Pit. The depth of the Pit varies from about 40 m at the western end to about 70 m at the eastern end.

8.3.5To utilize Blackwood Pit as a TSF limited earth works were required. The existing perimeter bunds around the Pit were extended where required to maintain a nominal 1m height and to divert storm water runoff. There was no disturbance of vegetation or removal of topsoil for these works. A water truck was utilized to control dust emissions from the earthworks.

8.3.5.1Tailing disposal pipes have been installed in a culvert under the road from the plant site to the eastern side of the Pit which, given its narrowness, provides sufficient discharge access. The eastern side also has a stable zone for installation of the main and for access to change spigot usage. The tailing main is 225mm HDPE pipe with 4 discharge spigots of 160 mm slotted HDPE pipes located at regular intervals along the side of the Pit. The discharge pipes will be slotted to allow delivery to the Pit bottom and to minimise the risk of erosion of the easterly Pit wall. The slotted discharge pipes will be progressively buried as tailing is deposited.

The pipes will be butt welded and will include flange connections where valves are required. Isolation rising stem gate valves will be installed to enable selection of which discharge spigots will be active. All pipework containing tailing outside of the Pit is bunded to contain any tailing in the event of a rupture or damage to the pipework.

The layout of the delivery and return lines at Blackwood Pit is shown in Figure 3.

Figure 3: Layout of the Delivery and Return Lines at Blackwood Pit

8.3.5.2A decant system will be used to extract water from TSF2 via two extraction lines at the north western end of the facility. Two extraction points are to be used to allow for potential migration of the decant pond which may result from changes in the tailing beach over the storage life. Extraction pumping will be from two 15kW submersible pumps located in slotted 560 mm HDPE pipes. The pipelines will have height markings on their sides to clearly display the height of the water in the decant pond. The Pumps will be suspended by cables which will be calibrated with height markings corresponding to those on the sides of the pipes so that the height of the pump can be controlled to maintain it in the decant pond. Decant water will be pumped via a 110 mm line to the lined Plant Water Pond for utilisation in the concentrator process.

When the decant water return is stopped the Plant Water Pond pump will continue to deliver to the mill circuit water tank until it reaches a low level at which point it will automatically stop. When rainwater or further TSF return water report to this Pond the pump will automatically start at the set operating level for the Pond. A gradation on the pump support walkway will provide a measurement of the water depth in the pond.

8.3.5.3The TSF will be operated to minimise the free water content of deposited tailing by managing the drainage to provide water to the decant extraction area and by placement of tailing at elevated pulp densities. The TSF management will also aim to minimize the area of the water pond at the decant to improve tailing drainage. This drainage plus evaporation will be the driving mechanism of strength gain and density increase for the tailing. Testwork conducted on tailing samples give an expectation that the density of tailing will be in the range 1.50 to 1.65 t/m3 as the tailing settles and dries.
8.3.5.4The properties of the tailing have been characterized as being relatively quick draining during the initial stages of deposition and then become a low permeability mass as consolidation proceeds. The permeability of the tailing near the base of the Pit is likely to reduce to approximately 5 x 10-10 m/s and the density of the tailing near the Pit bottom to increase to 1.7 and 1.9t/m3.

During the placement of tailing into the Pit initially some may flow into the partially filled voids that extend into the Pit. However, the fresh tailing are expected to settle in the old workings over a relatively short distance as the water is released from the high solids content tailing with blocking of the voids.