• Data Access
  • Your Email  
  • Your Email  
Keep me signed in.
Forgot your password?
Close
  • Forgot Your Password?
  • Enter the email you signed up with and we'll email it to you.
  • Your Email  
Close
Back
MDO
Mining Data Solutions
  • Home
  • Database
  • Subscribe
  • Sign In
  • Sign In
South Africa
Lace Mine

This page is not tailored to
devices with screen width under 750 px.
 Location:
24 km NW from Kroonstad, South Africa

  Address:
691 RUBY FARM
Kroonstad
South Africa
9499
Phone  ...  Subscription required
Fax056 216 1352
Additional Resources for Suppliers & Investors
Drill results over 30 g/t Au
Stay on top of recent discoveries.
Search drill results by commodity and grade.
Largest mines in the Americas
Mining and mill throughput capaciites.
Full profiles of select mines and projects.
Deepest underground mines
Shaft depth and mill throughput data.
Full profiles of select mines and projects.
Heavy mobile equipment
HME type, model, size and quantity.
Full profiles of select mines and projects.
Permitting and construction projects
Projects at the permitting or construction stage. Full profiles of select projects.
Mines with remote camps
Camp size, mine location and contacts.
Full profiles of select mines and projects.
Mines & projects in South Africa
A list of country's mines and projects.
Full profiles of select mines and projects.
  • Overview
  • Owners
  • Geology
  • Mining
  • Processing
  • Production
  • Reserves
  • Filings & News

Thank you for browsing through mine profiles compiled by the Mining Data Online team.

Would you like to subcribe or schedule a Demo?
  • Name:
     
  • Company:
     
  • Position:
     
  • Phone:
  • Email:
  • Message:

Overview

StatusInactive / Suspended
Mine TypeUnderground
Commodities
  • Diamond
Mining Method
  • Longhole open stoping
Processing
  • Dense media separation
Mine Life25 years (as of Jan 1, 2016)
DiamondCorp has entered administration in spring 2017.


Owners

Source: p. 10
CompanyInterestOwnership
Shanduka Resources. 13 % Indirect
Sphere Investment. 13 % Indirect
DiamondCorp plc 74 % Direct
Lace Diamond Mining (Pty) Ltd. 74 % Indirect
SA operating subsidiary Lace Diamond Mines (Pty) Ltd is owned 74% by DiamondCorp plc, 13% by Shanduka Resources and 13% by Sphere Investments.

Deposit Type

  • Kimberlite


Summary:

The Lace Mine lies within the south central Archean Kaapvaal Craton within a subcluster of kimberlites referred to as the Kroonstad Group II Kimberlite Cluster (Howarth, 2010) of which only Lace and nearby Voorspoed have seen formal mining. Four other small kimberlite blows and several dykes are known within the cluster.

The Lace Mine lies within the south central Archean Kaapvaal Craton within a subcluster of kimberlites referred to as the Kroonstad Group II Kimberlite Cluster (Howarth, 2010) of which only Lace and nearby Voorspoed have seen formal mining. Four other small kimberlite blows and several dykes are known within the cluster.

Drilling from surface through the wallrocks into the kimberlites in 1997-98 outlined a relatively simple stratigraphy of Karoo shales to ~60m, Ventersdorp volcanics to ~300m, an intercalated shale/volcanic sequence to ~350m, clean lavas again to 380m, and then Kameeldoorns Formation shales again to ~550m, the deepest wall rock drilling to date, in hole Crown-1. We therefore do not believe that Transvaal Supergroup rocks are present at Lace based on drilling to date.

The Lace kimberlites have been dated at 133.2 +/- 2.8 Ma by the 40Ar/39Ar technique on ground mass phologopite grains, similar to the early Cretaceous ages of the other Kroonstad kimberlites and to other Group II kimberlites in South Africa including Finsch.


Mining Methods

  • Longhole open stoping


Summary:

The report concluded that a continuous trough type doming mining method incorporating a sub level open stope mined from the bottom, best suits mining of the UK4 block. The greatest risk of mining any block close to old workings is the potential risk of inundation of water and mud from the old workings. The chosen mining method – called Longhole Open Stoping Bottom Up (LOSBU) - meets the requirements of the SIMRAC report on the guidelines to mitigate potential risk of mud rushes.

The LDM UK4 Upper Lift 1 block design layout comprises two main levels, namely a doming level (290m level) and the main production level (310m level) as shown schematically in Figure 3. Two open stopes are positioned to extract the required ore tonnage from the block. Two continuous troughs will be situated for ore collection below the Open stopes. The doming level will be situated on 290m level to enable doming long hole rings to blast ore down into the collection troughs. This ore will be loaded from draw points spaced along the troughs. One stope will be mined initially and once this has broken through to the old workings and the mud and water is dissipated and drawn down the second stope will be mined. Lift 2 on the 360m level will be similar, with the ultimate layout slightly larger.


Crushing and Grinding


Processing

  • Dense media separation

Source: Subscription required

Summary:

A front-end-loader (FEL) will feed 200tph run of mine material into a heavy duty scalping unit which have 500mm spacings.

All +500mm dump oversize will be removed by the scalping unit and broken up by a rock pecker. The -500mm ore is fed by a conveyor into a VGF (vibrating grizzly feeder). The VGF has 150mm spacings which drops out the -150mm onto a conveyor and thus bypasses the primary jaw crusher – the +150mm ore is fed into the jaw crusher which is set at 120mm (CCS). The crusher discharge drops onto the same conveyor belt as the -150mm ore and is transported to the primary scrubber. This conveyor is fitted with a weightometer for tonnage measurement and an overband magnet for tramp iron removal.

The scrubber feed conveyor discharges into the primary 2.4m diameter by 6.0m length scrubber complete with a double skin trommel. The scrubber feed material is mixed with water at a ratio of 1:1 in the scrubber and the material is disagglomerated.\ Primary scrubber ........

CommodityParameter

Production:

CommodityUnitsLOM (Projected)
Diamond carats 478,274


Reserves at December 31, 1998:

CategoryOreTypeTonnage CommodityGrade
Proven Tailings 2,853 kt Diamond 10.7 carats/t
Probable Tailings 742.3 kt Diamond 8.7 carats/t
Proven & Probable Tailings 3,596 kt Diamond 10.3 carats/t
Measured Tailings 2,853 kt Diamond 10.7 carats/t
Indicated Tailings 742.3 kt Diamond 7.6 carats/t
Measured & Indicated Tailings 3,595 kt Diamond 10.3 carats/t
Inferred Tailings 391 kt Diamond 4.3 carats/t


Heavy Mobile Equipment:

Subscription required - Subscription is required.


Corporate Filings & Presentations:

DocumentYear
Technical Report 2016
Subscription required - Subscription is required.

Aerial view:

Subscription required - Subscription is required.

Terms of Use Privacy Policy © 2020 MDO Data Online Inc.