Lesson 3 – VTN Operations

VTN OPERATIONS (SHEBA. CONSORT AND FAIRVIEW):

Underground operations

VTN operations are using conventional methods to extract Gold bearing ore at the workings i.e. winches, mono winches, shovels, picks, wheelbarrows etc and Electric powered vacuum machines.

Identification of working places

VTN Mine Overseer and Shift bosses are responsible for the identification of Gold reserves, by means of sampling of structures and pillars to determine the quantity of material and its Gold content.

Blasting of identified working area

Prior to the extraction of any Gold bearing ore, a risk assessment will be carried out by VTN and actual method of extraction will be documented.
The risk assessment together with the production method will be handed in to the BML Safety Department prior to blasting operation commence.
Ordering of explosives and storage as per Mine standard.
Primary and secondary blasting to comply with the Mines procedures and standards.

Entry into abandoned and old workings (recce’s)

Prior to entering such workings, the preparation and planning will include:
Obtained plans to identify route, travel ways, tips, ore passes, 2″‘ outlets etc.
Obtain as much geological, survey and sampling information as possible, to identify key targets.
Obtaining ore relevant data from Ventilation Department.
To inform BML mine overseer about “recces” to be done, to specify areas to be entered.

Team making entry

Equipment taken

Special area instruction for workings and travel ways

All VTN sections are worked-out stoping areas with pillars which VTN is planning and scheduling to remove. These areas are therefore classified as special areas as referred to in SOP1. Risk assessments must be completed on all working areas. The special support standards as specified below by the Consulting Rock Mechanic Engineer will be the minimum required standard for Sheba VTN workings, this special support standard must be read with SOP1.
Risk assessments in workings will determine whether a procedure for the specific area of work needs to be conducted, in which the standards below is not sufficient enough as per identification by the risk assessment.

Support

Temporary Support:

Laggings (100mm diameter) or Aero-jacks with headboards, to be utilized as temporary support for Machine Operators during drilling operations. Operators must drill under this support at all times, and temporary support not to be further from the face than 1,0m, to provide sufficient cover during drilling.

Permanent Support:

Mine poles (150mm diameter) to be installed at 2,0m intervals on dip and strike. Where geological disturbances, like faults or dykes, are encountered the support must be done on both sides of the geological disturbances, at 1,0m intervals in the direct vicinity of these disturbances.

General requirements:

Open areas where pillars must be removed, head-cover to be installed to provide cover for all workmen, in the area. These poles to be installed with jackpots. Head-covers only required where the inclination to the horizontal exceeds 20°.
Pillar area to be supported as per instruction, as prescribed in Permanent Support (2).
All the worked-out areas to be barricaded with barrier tape and where travelling through slope areas are necessary two (2) lines of sticks 3,0m apart, on either side of travelling-way, are required to identify safe travelling area and barricaded with barrier tape.
Access to these areas must be identified and making safe to be done in accordance with SOP 1.
Refuge chambers to be identified on all plans and workmen must be clearly instructed and knowledge thereof tested on a monthly basis.
Special instructions to be signed off on a monthly basis and communicated, by all Supervisors, to the workmen in these areas.

Procedure for the filling of VTN bags

Ore bag to be placed inside of material car.
4 x corner loops attached to bag must be tied to top rail of material car construction with twine rope.
Material car must be stationed beneath box front by 2 assistants.
Box operator must open the box radial door with control on amount of ore entering the bags to prevent spillage and over loading of bags.
Upon filling of bottom bag, the box operator must close the box front radial door. The ore must be scraped from the box front chute into the bag.
The box operator must inform the 2 assistants that the box front chute is clear of ore.
Assistant to lose twine rope from corner loops attached to bag.
The two assistants must place no.2 bag on top of no.1 bag of material car.
The four corner loops attached to the bag must be tied to the loading platform with twine rope.
The two assistants must inform the operator that the corner bag loops have been secured to loading platform.
The box operator to discharge the ore into the bag. The ore must be fed into the bag controllably to prevent spillage and over filling of the bag.
Upon completion of filling the bag, the box operator must scrape ore from the box chute into the bag.
Box operator must inform the 2 assistants that ore has been removed from the box chute.
The two assistants must loosen the twine from the box loading platform.
The 2 assistants must push the material car from the loading point beneath the box front

Filling of hoppers\material cars from timber box

The construction of a timber box consists of two L-Brackets with gum plank gates. The top gum plank gate must always be in a station position. This gum plank gate prevents the ore from running out of the box uncontrollably. The bottom gum plank gate must be pushed upwards only from one side to allow the ore to drain underneath of it from the timber box. The other end of the bottom gum plank gate must be kept inside of the L-bracket. The end being lifted must not be taken out of the L-Bracket.
When the required ore for filling the hopper\material car have been discharged, the bottom gum plank gate must be pushed down in to position to stop the flow of ore from the timber box. When filling material cars, the procedure as above for filling material cars must be followed.
For shaft specific procedures refer to SOP!!