Coal mining is a long-standing tradition associated with the inhabitants living at the forests in Ca Mau. Compared with many places in the country, there are no places in our country produce more charcoal than in Ca Mau province.
 

The model of coal tunnel built the kiln first, and then put the wood to the tunnel. Photo: Pham Hoang.

According to many archives, before 1945, Ca Mau province had over 700 coal mining stoves. In late 1954 and early 1955, Ngo Dinh Diem and Ngo Dinh Nhu went to Ca Mau to exploit mangroves coal. Particularly Tran Le Xuan (wife of Ngo Dinh Nhu) “open cup”, coal furnace building. In 1959, Tran Le Xuan produced 60,000 tons of coal. In the following years of liberation, the remains of coal kiln of Tran Le Xuan still exist in many places in the mangrove forest area of Ca Mau.

For many forest dwellers in Ca Mau, coal mining are one of the livelihoods, providing fuel to the market.  

Coal materials are mainly all timber species living in mangroves and floodplains in Ca Mau. However, Ca Mau people often use for charcoal are mangroves, melaleuca, etc. Normally, before putting into the coal mining, the raw material must be cut, fresh, peeled, cut short by specifications.

Nearly a century ago, the way coal mines in Ca Mau have remained unchanged, and there are two main models: the coal mining without fixed furnace (pre-fired charcoal then build the furnace for tunnel) and the building the stove first then put the wood to the coal mining.

The coal mining without fixed furnace method. Photo: Huynh Lam.

The coal mining without fixed furnace: Before mining, the wood is laid on the ground or peeled off the ground about 3 to 4 inches. Digging down makes the furnace feet more stable, airtight and keep the heat. Use litter grass around the block of firewood to prevent the mud that sticking to the firewood, creating the necessary airflow to allow diffused heat, with drainage holes for smoke and water to escape. After that, take the  riverbank mud to fill wood in the necessary manner. When sealed, the furnace was cut a door (about 1.5 inches x 3 inches) to set fire. In addition to the oven door, the oven is also picked some smoke holes to allow smoke and water to escape. The oven door is located close to the bottom of the furnace and the above is wind direction to ensure continuous fire. Then, proceed to burn the furnace. Normally, the furnace burns about 24 to 48 hours (depending on the small and large furnace) is finished.
 

Gleaning coal. Photo: Huynh Lam.

Brick mining: Brick built, solid, stable, scale than other coal mining models.

When processing, charcoal is arranged vertically or horizontally. When arrange the wood is often turned (big - small, up - down) to tight, evenly. The tighter the wood is, the better. If the arrangement is loose, the fuel wood - coal will decrease, the coal is not ripe, difficult to follow in the processing and coal easily shredded, damaged. When the firewood arrangement is finished, the firewood door is arranged together and plastered to seal and fire at the oven door. During the coal processing, fire must be burning continuously. With a furnace diameter of about 4 meters must be burning continuously for about 10 days and night, the new coal can be ripe. Good coal processor can see the smoke and the smell of coal is to know whether the coal is ripe or not. After determining that the inside coal has been rinsed, use a paste land to seal all furnace doors, openings and fissures, preventing oxidation from entering the outside of the furnace to cool the furnace and cooling the coal. Then proceed to unloading, harvesting products.

Today, due to the development of science and technology with many gas stoves, electric stoves, magnetic stoves, induction stoves and most of the forest area is seriously reduced, so charcoal stoves in Ca Mau are gradually lost.

Coal mining has just been announced by the People's Committee of Ca Mau province on the list of 40 intangible cultural heritages in the province so that branches and localities can preserve and promote the values and manage them according to the regulations of the law.