Beneficiation involves the treatment of raw materials to improve their properties - in the process value is added to these materials. During the period 1991 to 1996 a number of beneficiation projects were undertaken in the private and public sectors, requiring substantial capital investment running into billions of rand. The civil engineering industry plays a major part in the execution of these projects and can take much of the credit for their timeous and successful completion.
The Chalumna River Bridge near East London incorporates the first external prestressing on a new bridge in South Africa and is the first bridge launched on a double curvature in the country The Chalumna River Bridge, on the coastal road some 40 km south-west of East London, is on the new alignment of Trunk Road R72 between Sandile and Lilyvale and crosses the Chalumna River near the coast. The bridge was officially opened by the Eastern Cape Premier, Raymond Mhlaba, in March this year. The project was one of the finalists for SAICE's 1996 National Award for the Most Outstanding Civil Engineering Achievement.
Over 25 years of operation, Alusaf's Bayside Smelter had grown and prospered, expanding its production capacity during the early 1980s to the current level of 170 000 t per year. At the beginning of the 1990s, Alusaf faced the task of reinventing itself to meet the competitive challenges brought about by South Africa's re-entry into the international arena.
This article looks at the development of the Columbus Stainless Steel project, which aims to make South Africa a world leader in this field The vision The idea of establishing a world leading stainless steel producer in South Africa has been around for a long time, but only began to crystallise in the mid- 1980s. At the time both Samancor and Highveld Steel and Vanadium were investigating the possibility of establishing a stainless steel producer in South Africa. In the late 80s the two companies decided to pool their resources. Several options were considered.
The heavy mineral deposits at Brandse-Baai are situated on the Cape West Coast about 80 km west of Vredendal and extend 14 km inland from the coastline. The world-class heavy mineral ore reserves cover about 5 000 ha, with the three valuable heavy minerals of interest to Namakwa Sands being ilmenite, zircon and rutile. A mineralised coastal dunefield lies just north of the main deposit. Although it has the potential to provide a further R400 million worth of minerals, it will not be mined for environmental reasons, while a 300 m beachfront area will similarly be protected from mining activities.
This article outlines the process involved in converting sludge from wastewater into compost, thereby solving a major sewage treatment problem and at the same time providing a useful by-product The disposal of wastewater sludge is one of the most pressing problems facing large urban authorities responsible for the treatment of wastewater. The Greater Johannesburg Transitional Metropolitan Council (GJTMC) Wastewater Department is not excluded from this dilemma. Sludge is the waste product from the beneficiation of wastewater into 'clean' water. The environmentally safe disposal of wastewater sludges has generally been concerned with converting an unstable waste into a stable or inert waste, eg disposal to sacrificial land and landfills, incineration into ash, etc.
The recent ruling of the Riversdale Magistrate's Court that found the condition of the road to be responsible for the horrific bus accident there in 1994 has considerable financial and moral implications for SA road authorities. The Riversdale accident happened on a section of road where tyre skid resistance was dangerously low, aggravated by moist conditions and a significant divergence of skid co-efficient between the left and right wheel tracks. It happened 170 m before a sign indicating a reduction in speed to 80 km/h.
In my article introducing environmental law (Civil Engineering, December 1995), brief mention was made of the environmental provision contained in our Interim Constitution (Act 200 of 1993). Subsequent to its enactment much has been written regarding the entrenched environmental right. This criticism has been both positive and negative. Our soon to be adopted final Constitution, which was recently adopted by Parliament, once again contains an environmental right, which is to be found in Chapter 3 which deals with our fundamental human rights. There will again be criticism of the section's content and ambit, and I will attempt in this article to anticipate what such criticism will relate to and the possible effects the section may have on the civil engineering profession.