Marunic has access to every spec and sizing of coal produced in South Africa. 

As a South African company with offices and distribution depots throughout the nation, we provide products and services that businesses in a variety of industrial and agricultural sectors need, including:

Industries we supply

  • Cement
  • Clay Brick Manufacturers
  • Domestic Heating
  • Farming & Nurseries
  • Foundries
  • Hospitals and Prisons
  • Manganese
  • Paper, Pulp & Plastics
  • Poultry
  • Steel & Metal
  • Textile & Clothing
  • And More

We have an exceptionally positive reputation in the marketplace for going beyond expectations. The amount of repeat and word-of-mouth business we attract proves that. Our skilled professionals with knowledge and experience in trading, logistics and finance are the reason we can serve so many clients so well.

The quality of our products and the depth of our commitment to logistics are also among the reasons so many companies in so many industries trust us with their needs. In fact, our services include comprehensive supply chain and management solutions that guarantee on-time product delivery.

Location, location, location

Another of our company’s secrets to success is our presence in key supply and distribution locations. Marunic Trading’s administrative head office is located in George in the Western Cape. We also have regional offices in Hwange, Zimbabwe and Kitwe, Zambia and supply products from distribution depots in Vereeniging and eMalahleni (Witbank). Our Transport Division resides at head office in George.

For the high-quality commodities and logistical services your company needs to do its best work, turn to Marunic Trading. Our complete array of products and services is just a phone call or email away.Contact Us to see how we can serve your company.

COAL GRADES:                                                  

A Grade:   >27.5 CV

B Grade:    26.5 – 27.5 CV

C Grade:    25.5 – 26.5 CV

D Grade:    24.5 – 25.5 CV


Cobbles:        75mm – 125mm

Large Nuts:   45mm – 75mm

Small Nuts:   25mm – 45mm

Peas:               8mm – 25mm

Duff:                2mm – 6mm

Spiral:             <3mm



Metric ton (t)
= tonne = 1000 kilograms (= 2204.6 lb)
Imperial or Long ton (lt) = 1016.05 kilograms (= 2240 lb)
Short (US) ton (st) = 907.19 kilograms (= 2000 lb)

From long ton to metric tonmultiply by 1.016
From short ton to metric tonmultiply by 0.9072
Mt – million tonnes
Mtce – million tonnes of coal equivalent (= 0.697 Mtoe)
Mtoe – million tonnes of oil equivalent

Calorific Values (CV)

kcal/kg –
Kilocalories per kilogram
MJ/kg* – Megajoules per kilogram
Btu/lb – British Thermal Units per pound
* 1 MJ/kg = 1 Gigajoule/tonne (GJ/t)

Gross & Net Calorific Values

Gross CV or higher heating value’ (HHV) is the CV under laboratory conditions.
Net CV or ‘lower heating value’ (LHV) is the useful calorific value in boiler plant. The difference is essentially the latent heat of the water vapour produced

Conversions – Units

From kcal/kg to MJ/kg multiply by 0.004187
From kcal/kg to Btu/lb multiply by 1.800
From MJ/kg to kcal/kg multiply MJ/kg by 238.8
From MJ/kg to Btu/lb multiply MJ/kg by 429.9
From Btu/lb to kcal/kgmultiply Btu/lb by 0.5556
From Btu/lb to MJ/kg multiply Btu/lb by 0.002326

Conversions – Gross/Net (per ISO, for As Received figures)

kcal/kg: Net CV = Gross CV – 50.6H – 5.85M – 0.191O
MJ/kg: Net CV = Gross CV – 0.212H – 0.0245M – 0.0008O
Btu/lb: Net CV = Gross CV – 91.2H – 10.5M – 0.34O

– where M is % Moisture, H is % Hydrogen, O is % Oxygen (from ultimate analysis*, also As Received).

* Ultimate analysis determines the amount of carbon, hydrogen, oxygen, nitrogen and sulphur.

For typical bituminous coal with 10% M and 25% Volatile Matter, the differences between gross and net calorific values are approximately as follows:

260 kcal/kg 1.09 MJ/kg 470 Btu/lb

Power Generation

1 MWh = 3600 MJ
1 MW = 1 MJ/s
1 MW (thermal power) [MWth] = approx 1000 kg steam/hour
1 MW (electrical power) [MWe] = approx MWth / 3

A 600 MWe coal-fired power station operating at 38% efficiency and 75% overall availability will consume approximately:
– Bituminous coal (CV 6000 kcal/kg NAR*): 1.5 Mt/annum
– Brown coal (CV 2250 kcal/kg NAR*): 4.0 Mt/annum

* Net As Received