The Sugar Refining Process
Mhlume's operation is set up in two basic parts. The estate operation is concerned with cultivating and harvesting the sugar cane and transferring it to the mill; the mill operation then takes the raw sugar cane and processes it into brown sugar. (Making white sugar involves further processing which the Mhlume mill is not equipped to do at this time.)
The estate's harvesting cycle begins roughly around 1 May each year and ends roughly in November or December. (The company's fiscal year also coincides with its physical operations.) Harvesting the cane involves two basic steps. First, the standing fields of sugar cane are burned. Burning removes the leaves from the standing cane and facilitates the harvesting process. Without the process of burning the fields, the cane would have to be harvested with its leaves intact; the leaves would then have to be removed during the milling process. Further, burning the fields heats up the sucrose inside the cane, making it easier to work with. In addition, burning the fields drives away the native snakes, making it safer for the workers to cut the cane. Eventually, environmental laws in Swaziland may prohibit burning the fields prior to harvest; at that time, Mhlume and other sugar processing plants will have to revise their harvesting and milling procedures.
After burning the fields, the sugar cane is harvested. Migrant workers are engaged each year to cut down the cane by hand. Workers are paid a fixed daily salary with the possibility of earning incentive pay for cutting more than their daily quota. Harvesting the cane is a very labor intensive process, making it well-suited to the Swazi economy, where labor resources are plentiful but machinery is not.
The cut cane is transported to Mhlume's mill. On arrival at the mill, the cut cane is crushed to extract the liquid from its core. (The crushed cane can then be burned, producing the by- product bagasse, which is used to fuel the mill's machinery.) The liquid is heated, causing the sucrose to fall to the bottom where it can be collected for further processing. At this point, the sucrose itself is dark and thick, resembling molasses (indeed, molasses is the other by- product of the process). Chemicals are added to the sucrose to cause crystallization into the brown sugar that is the mill's principal product.
With good soil, sugar cane is a perennial; that is, the cane will grow back every year without re-planting. However, because the Mhlume estates have poor soil, the cane must be re-planted approximately every five years. A specially grown seed cane is used to re-plant the fields on a rotating basis. Mhlume produces about one-third of Swaziland's total sugar output annually (the kingdom's total annual sugar output is about 450,000 tons). Approximately one- third of the kingdom's total output is used internally, with the remaining two-thirds being sold on the world market.