Environmental Impact Assessment of a Scrap Metal Smelting Plant

INTRODUCTION

Huge amounts of scrap metals are being generated on a daily basis and can pose environmental damage if not recycled (Danielson, 1973). A company in Willowvale, Harare, Zimbabwe intends to embark on a smelting plant project of solid metallic components in the area. The company has identified the need to smelt scrap metal for molding purposes. The smelting plant will melt the scrap metal for use by other individual companies. The smelting of metals is critical in the sense that most of the waste metal lying idle will be reused, thereby promoting sustainability.

Since the Environmental Management Agency (EMA) requires that all development projects should have an Environmental Impact assessment (EIA) report before implementation, this report fulfils that requirement. This EIA document describes the environmental impacts identified, outlines mitigatory measures, and points out how the proponents can manage the negative environmental impacts caused by the operations of the project. The environment in the project area as divided into the biophysical environment, the economic environment, and the sociocultural environment needs careful analysis so that minimal negative impacts are realized or, rather, avoided at all costs. The EIA report is an important tool in the project planning, development, and decision-making processes. The report should provide accurate, useful, and relevant information so that the environment is protected and that the proponents of the project conform to the dictates of the law for sustainable development.

NECESSITY AND SCOPE OF THE ASSESSMENT

A scrap metal smelting plant has some negative environmental impacts associated with its development. There are air, land, water, and noise pollution issues, as well as chemical waste issues. It is therefore the main objective of this report that these issues are addressed to minimize environmental damage in accordance with the laws regulating the establishment of such developmental projects.

In order to have an appreciation of the project area, the consulting team must make visit to relate the current economic activities taking place in the area of the proposed project. Fuerthermore the activities of the new project on how they would impact the immediate environment and in some ways affect distant environment through fluvial processes. The data collection process included the following aspects:

i. Emissions

ii. Traffic or vehicular movement patterns

iii. Land use patterns

iv. Noise pollution

v. Waste management (solid and effluent)

IMPACT IDENTIFICATION

After an analysis of the collected data, the consultancy conducted an impact identification process of the project. This entailed identifying the potential negative environmental impacts of the project from project design up to the decommissioning stage. A Six Activity Model was used for the production of the El A report. This model has been used by the consultancy over time and consists of the following steps:

i. Current environmental status description

ii. Acquisition of relevant standards or guidelines

iii. Determination of potential impacts of the proposed project

iv. Impact prediction

v. Determination of impact significance

vi. Determination and incorporation of mitigation measures

ENVIRONMENTAL MANAGEMENT PLAN

An environmental management plan (EMP) is a tool that is used for checks and balances in the life of the smelter plant. In the EMP, the potential environmental impacts and mitigatory measures are identified and evaluated to indicate the levels of severity of the impacts to the environment. The EMP also provides the mitigatory measures that address the negative impacts.

SMELTING PLANT EIA PROCESS

The study progresses in the following manner: provides a description of the site, describes the proposed components of the project, reviews the policy context in which the environmental impact assessment has been carried out, presents an environmental management plan for the project, and gives a summary and conclusion of the EMP.

SMELTING PLANT BASELINE STUDY

The smelter plant sits on approximately 2 hectares of land. The heavy industrial area is to the North of the plant.

Area Hydrology

The area on which the smelter is to be established is generally flat and covered with a variety of grass and shrub species. The soils are generally black clays, and the drainage is poor in these soils. The area is vlei-like, but this is seasonal, as waterlogging only occurs during the rainy season. Reeds in the stream channel suggest that there water present in the area, which can be described as a wetland, though it is not a fully-fledged wetland.

Vegetation

The project site surroundings are covered by riverine grass; no woody species were identified. Grass species compatible with waterlogged areas are prevalent on the project site, and the entire setup looks swampy. These grasses are spread within the project site surroundings and are thriving because of the rainy season. The common grass species present are the Sporobolas spiramidalis, Paspalam puverli, Typha capensis, and the speras.

There are also a couple of reeds on the premises, indicative of intermittent high water and a swampy area. It is important to note that during the summer season, the project site displays an abundance of water but will decrease in winter due to less rainfall. These may also be attributed to some pits which had been left open and then later disused. The soil type is black and deeply saturated with water, the soil grains adhering to each other. These clayey soils leave small air spaces within them leading to soil with generally poor aeration.

Climatic Conditions

The savannah climate prevails in the project area, as Harare lies in Region 2 of the agro-ecological regions of Zimbabwe. Rain falls from mid-October to April. The peak rainfall period is between December and February. Harare receives about 860 mm of rainfall per annum. Temperatures are highest in October and November, whilst the lowest temperatures are experienced in June and July. The average temperature is 22°C, with a diurnal range of 14°C in summers while in winter it is 22°C. Evaporation rate is high in summer months because of the high rainfall and high temperatures; it is conversely low in the winter months due to low rainfall and temperatures.

Air quality monitoring still presents a challenge in the country due to the lack of modern and sophisticated testing equipment. EMA is said to have recently acquired some testing equipment, but there is limited use of the equipment. Potential air quality violations are based on the use of known combustible fossil fuels; particulate dust emissions (soot and fine ash) are also introduced to the atmosphere together with the smoke. The air in the industrial area is characterized by the presence of the identified gases and the particulate matter arising from the combustion of the fossil fuels used in industry. Between these pollutants and the general wind movement from east to west, the air quality in the western parts of the industrial area is poor.

Water Quality

Harare is part of the Lake Chivero catchment area and several rivulets and or ephemeral streams pass through the city’s industrial area into the Hunyani River system.

The water quality and testing laboratory managed by the EMA conducts water quality testing. District environmental officers and provincial officers submit water samples for periodic testing at the lab. In most cases, water quality testing is done when an environmental accident happens which introduces pollutants to the river channel systems. Harare City Council (HCC) has the sole mandate to procure and provide potable water for use in the area under the jurisdiction of the city council. The water is treated at Morton Jaffray Water Treatment Works near Norton. The water is then delivered to Harare through a network of pipelines and there are pressure booster stations at strategic places in and around Harare. The water is delivered to homes and industry by the HCC.

DESCRIPTION OF THE SMELTING PROJECT

After the government banned the export of scrap metal, the company currently doing business in the industrial area recognized a business opportunity and decided to establish a steel smelting plant. The government observed that there was so much scrap metal being exported to the Republic of South Africa, and that smelting of scrap metal in-country has both economic and environmental benefits: job creation, energy savings, and less reliance on metal imports. On the environmental side unwanted scrap metal pollutes the land. By smelting it, the environment is rid of unused and unwanted metal which is then recycled and stored in the form of ingots for use in the future. And because rusty metals are a source of tetanus, (a disease that causes muscle spasms and rigidity), recycling scrap metal promotes hazard-free playing environments for children and safer workplaces, where injuries from unwanted scrap metal are reduced. The metallurgical process in industry is shortened as part of the metal is readily available in the form of scrap metal.

Plant Location

The smelting plant shall be located in the Willowvale industrial area. This area is home to existing heavy and light industrial works from metal works to plastics engineering. The smelter plant brings an advantage to metal engineering firms in that the smelter products may be readily acquired by the industries in the locality of the smelter plant.

Smelting Process

Smelting of the metals or ore requires a furnace designed by engineers according to the requirements of the project proponent. The smelting plant shall operate on a 24-hour basis and shall have routine planned maintenance programs to ensure safety and efficiency. The processing of scrap metal requires the following components to be fully operational:

Transportation of Scrap Metal

A ready stockpile of scrap metal is a general requirement in order to keep the furnace operating. When the furnace is turned on, certain temperatures need to be maintained to avoid the collapse of the furnace structure. Starting the furnace and getting it to the required temperature is a slow and expensive process. Trucks shall be used to ferry the scrap metal to the plant. The daily expected delivered tonnage shall range between 120 and 150 tons of scrap metal. A weigh bridge shall be put in place to weigh the trucks before they proceed to the stackyard.

Stackyard for Scrap Metal

The stackyard is the place where all the scrap metal is deposited. The area shall have a concrete top of an excavated and gravel compacted base to accommodate the heavy trucks. The scrap metal shall be sorted according to types and stacked in rows with clearance in between them to allow vehicular and wheelbarrow movement. A scrap metal hydraulic compactor shall be introduced to enhance the storage of the scrap metal.

Receiving Section

Wheel barrows and or hydraulic carts shall be used to move the scrap metal from the stackyard to the receiving (intake) section of the smelter where it is then fed into the furnace. The receiving section has a ramp about 1 m in height elevating from the ground level to the top of the smelter. The scrap metal is then fed into the smelter from the top.

Section for Smelting

The smelter shall have 2-3 m of its total height encased in concrete. There will be two chambers on the furnace and these will receive approximately 1000 kg (1 ton) of scrap metal each. The chambers will be tightly closed, and the scrap metal is subjected to highly pressurized heat for one and quarter hours (1 hour and 15 minutes). The scrap metal starts to melt into molten liquid where 90% of the scrap metal is recovered while 10% is lost as waste or burnt completely. The burnt component would be the rust and other materials like plastic washers and paint that come together with the scrap metal. Hydraulic mechanisms pour the molten liquid into melds that are 6 cm wide and about 1.0-1.5 m in length. When cooled the bars are then referred to as ingots which weigh about 23 kg and are stacked in a shed for further processing into various forms of steel. Such a process is envisaged to bring high yields. The plant will use 2000 MV of power and a dedicated power line from a nearby Zimbabwe Electricity Transmission and Distribution Company (ZETDC) will supply the plant with power. The dedicated power line is an essential component of the project because electricity interruptions can cause damage to the plant. The plant also uses coking coal for the smelting process.

Labor for Smelting Plant

The smelting plant requires a 45-man strong labor force of both skilled and unskilled personnel for the plant to be fully operational. The labor force may be categorized as:

i. Management and administration 6

ii. Skilled and semi-skilled 21

iii. General and unskilled 18

The staff compliment above has various skills and functions in the whole process chain.

By-products of the Smelting Plant

Modern smelters are efficient both in energy and process efficiency. Smelting of scrap metal, unlike the smelting of mineral ore, produces little or no solid wastes. The impurity level in the scrap metal is very low and takes the form of paints, rust, and other components such as plastic and paper washers. These completely burn out or produce little waste. Less than 10% of the total weight charged into the smelter is lost in the process.

Existing Infrastructure

The smelting plant has various existing infrastructure.

Water Supply

The HCC has a w'ater supply infrastructure to supply the smelting plant. The water supply is the City Council’s responsibility as it has the lawful mandate to be the sole operator and supplier of potable domestic and industrial water through its water supply infrastructure. The water is for cooling and cleaning purposes. The water from the cooling system is recoverable on site. A storage tank shall be constructed at the site to ensure availability of water at the plant in the event of failure in the city supply line.

Sewage System

Liquid waste water from the ablution block, canteen, and spillage from the smelter plant shall be disposed of through the City Council sewage system. The volume of liquid waste matter is low due to the small labor force at the plant. The smelter discharges minimal water through accidental spillage where this w'ater collects on the floor and gets dirty.

Electricity

The ZETDC has electricity grids to supply the various industries in the area. There is a ZETDC substation within a short distance from the proposed plant. The company is presently serviced by an 11 KV line, but this line shall be upgraded to supply 2000 MV to the smelter. The company shall also install a standby generator should there be interruption in electricity supply.

Road Access

The area where the plant is located is serviced by tw'o major roads namely Willowvale and High Glen Roads. It is unlikely that traffic to and from the plant will cause any congestion, as only 3-4 trucks are expected at the plant on a daily basis to offload scrap metal.

Administration Block

There is an existing building on the site which currently houses administrative offices. This building was left by the previous occupant. The company is in the process of upgrading the building. Another building shall be erected to house the canteen, workers’ changing room, and toilets.

 
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