MVS Symposium

“ In - Stope “ Ventilation Control

Regulatory Considerations Related To

“ In Stope “ Ventilation Control

R J Gilmour - Harmony Gold Mining Company LTD

Agenda

•Introduction
•Regulations I
•Regulations II
•Codes of Practice
•Risk Assessment
•Implications On Current Work Practice
•Minimise Impact
•Conclusion
•Question / Discussion
•Acknowledgement

Introduction

The most important weapon in the fight against

Flammable gas, Heat and Airborne Pollutants is good

air flow at the working face.

However, in many instances the ventilation provided

at the stope entrance does not always reach the

working face because of poor “ In – Stope”

ventilation control. The air often flows straight up

the centre-gully or short circuits the face and flows

into the “worked out” back areas of the stope.

Regulations I

•Mines and Works Regulations repealed in July 2002:

106 regulations in 9 chapters

• Regulations promulgated under MHSA(1996) in July 2002 :

21 regulations in 4 chapters

Regulations II

New regulations replacing old regulations !
•So what?
•A regulation is a regulation!

•OLD :

Prescriptive

: eg) Reg. 10.7.1 The velocity of the

air current along the working face of any stope shall

average not less than 0.25m/s over the working height;

and ……..

•NEW :

Outcomes Based

: eg) Reg. 9.2(1) The Employer

must ensure that the occupational exposure to health

hazards of employees is maintained below the limits set

out in Schedule 22.9(2)(a) and (b).

Codes of Practice

•Mandatory : Compile in line with approved guideline:

-

Airborne Pollutants ( potentially 608 )

-Thermal Stress ( Heat and Cold )
- Flammable Gas

•Voluntary : eg) Ventilation Code of Practice:

-

Existing mine standards

- Include “old” regulations as standards

Risk Assessment

(Section 11 of MHSA, 1996)

•Identify hazards to health and safety - heat, cold, radiation, flammable gas,

airborne pollutants

•Assess risk to health and safety - how much vs. hazard limit

•Record significant hazards and risks - which

•Make records available - data base, vent reports

–LEADING TO:

Determine all measures, including changing organisation of work (Blasting re-

entry) and design of safe systems of work necessary to:
•Eliminate any risk -
•Control risk at source - drilling with water
•Minimise the risk - Air volume > flammable gas
•Remaining risk - PPE ( respirator);

- Programme to monitor risk( gravimetric sampling for dust)

Implications On Current Work Practice

•Face velocity : dust, gasses and heat

•Face temperature : cooling power = work performance

•Re-Entry after blast : dust and gasses

•Radiation : Radon gas ( progeny)

Minimise Impact

Improve, maintain and optimise

“In - Stope “ Ventilation Control

Conclusion

GOOD

STRIKE CONTROL and GULLY BRATTICING

KEEPS THE AIR ON THE FACE

WHICH

MAINTAINS A HEALTHY and SAFE

OCCUPATIONAL ENVIRONMENT

Questions ?

Discussion !

Acknowledgement

Mine Ventilation Society of South Africa

(Free State Branch)

Harmony Gold Mining Company Limited