Design Life-Cycle

Patti Cai

Professor Cogdell

DES40A- Section03

Winter2016

Research essay

                                                       Grundtal Toilet Roll Holder Life Cycle—Wastes 

Grundtal Toilet roll holder is the simplest one in design in Ikea’s toilet roll holder series but is also the most applicable and durable one. The entire holder, combining the plug, tube and wall bracket, is made of stainless steel. My research focuses on wastes generated from the whole life cycle of this stainless steel product, which includes wastes from its raw material’s mining process, its fabricating process, and its final recycling process.

Firstly, why does the producer or designer use stainless steel as the basic material of their product? When choosing the material for production placed in the bathroom, the producer should be first of all considering the material’s ability on moisture resistance. Being long placed in a humid environment, metals will be corroded; the deterioration or breakage of metals inside products will cause them losing their original uses. So an anti-corrosive and moisture-resistant material is needed for bathroom appliance.

Stainless steel is the material that perfectly matches these requirements.  Its remarkable resistance to corrosion is due to a chromium-rich oxide film which forms on the surface. When ordinary carbon steel is exposed to rain water, for example, it corrodes forming a brown iron oxide, commonly called rust, on the surface. This is not protective and eventually the entire piece of steel will corrode and be converted to rust. But when enough chromium (more than about 10%) is added to ordinary steel, the oxide on the surface is transformed - it is very thin, virtually invisible and protective in a wide range of corrosive media. (Coates, 2016).

            The first step of the whole production of Grundtal toilet paper holder is the mining process of ore materials. After that, ores are produced to iron and then to stainless steel. Wastes are generated from the very first step of the production chain. Extraction and beneficiation process produces iron or steel. "Extraction" is defined as removing ore material from a deposit and encompasses all activities prior to beneficiation. "Beneficiation" of iron includes concentration, generally by physical removal of unwanted gangue; also considered beneficiation is the regulation of product size or other steps such as agglomeration to improve its chemical or physical characteristics prior to processing. Most ores extracted today, however, must undergo a number of beneficiation procedures to upgrade the iron content and prepare the concentrate for the blast furnace. Technological advancements at blast furnace operations require ore feed of a specific size, structure, and chemical make-up for optimum efficiency (Weiss, 1985)

So it is inevitable that the iron ore extraction and beneficiation process discharge various kinds of wastes and other materials: Waste rock, wastes from magnetic separation, milling wastes, flotation wastes, and mine water. Each kind of waste has its own recycling or managing method accordingly:

 -  Waste Rock is the material that overlies the ore body and the other rock that has to be removed to gain access to the ore. The quantity and composition of waste rock vary greatly between sites. These wastes contain minerals associated with the ore body and host rock. The materials can occur in a wide range of particle sizes owing to variations in ore formations and differences in mining methods. In many operations, waste rock is disposed of in piles located near the mine (Van Ness 1980). It also can be used in dams or other on- or off-site construction. Overburden and waste rock removed from the mine are stored or disposed of in unlined piles onsite. These piles may also be referred to as mine rock dumps or mine dumps. As appropriate, topsoil may be segregated from overburden and mine development rock, and stored for later use in reclamation and revegetation. These dumps are generally unsaturated and provide an environment that can foster acid generation if sulfide minerals, oxygen, and water are present. However, in Minnesota and Michigan, where most crude iron ore is produced, sulfide-bearing minerals are present in only one unique geologic environment, according to the American Iron Ore Association (Guilbert 1986), so acid generation should not be a problem elsewhere. Ore is also stored in piles at the mine or mill before beneficiation.

- For milling dust, most mills use a wet milling operation and employ water to control dust from crushing and grinding. Slurried value-bearing process water from dust control contains both suspended and dissolved solids. The solid content of the slurry varies with each operation, ranging between 30 and 60 percent. The dust control slurry is typically pumped to a ball mill overflow/hydro cyclone feed sump for further beneficiation (U.S. EPA 1976)

-  Magnetic separation wastes and material is the primary wastes from magnetic separation are tailings made up of gangue in the form of coarse- and fine-grained particles and waste water slurry in the case of wet separation. Particulate wastes from dry separation may also be slurried. Following separation of solids in a thickener or settling pond, solids are sent to a tailings impoundment and most of the liquid component can be recycled to the mill or discharged if water quality criteria are met.

-  Flotation wastes and materials discharge from a typical floatation cell system is mostly gangue material and small quantities of unrecovered iron minerals. The liquid component of flotation waste is usually water, along with any remaining reagents not consumed in the flotation process. The liquid component may then be used in other mining activities as needed or discharged if water quality criteria are met. The characteristics of tailings from the flotation process vary, depending on the ore, reagents, and processes used.

-  Gravity concentration wastes and materials from gravity concentration are mainly tailings. Tailings are characterized by fine particle size and varying mineralogical and chemical composition (Aleshin 1978). Tailings typically take the form of a slurry consisting of water, with solids from flotation, magnetic separation, and/or agglomeration. This material has minimal value at present but is produced in extremely large quantities. The solid content of this kind of slurry varies with each operation, ranging between 30 and 60 percent. Following the separation of solids, process water may be recycled to the mill or discharged if water quality criteria are met.

-  Agglomeration Wastes and Material contains carbon dioxide, sulfur compounds, chlorides, and fluoride metals and other ores. These wastes are usually collected using cyclones, electrostatic precipitators, and scrubbing equipment and create both dry and slurry forms of waste. The waste is commonly combined with waste water generated during other production operations for treatment (typically settling and/or thickening). Solids are returned for recycling through the process, and the liquid component can be recycled to the mill or discharged (U.S. EPA 1985b).

-  Mine water consists of water that collects in mine workings, both surface and underground, as a result of inflow of rain or surface water, and ground water seepage. As discussed previously, mine water may be used and recycled to the beneficiation circuit, pumped to tailings impoundments for storage prior to recycling or for disposal, or discharged to surface water under an NPDES permit. (Technical Resource Document, 1994)

After raw materials are extracted and beneficiated, they are processed into iron and then into stainless steel, through the furnacing and fabrication processes, more wastes are generated at the same time. It is estimated that wastes containing over 20 million lb of chromium and 8 million lb of nickel are generated annually in the production of stainless steel in the United States. These wastes, consisting of flue dusts, swarfs and mill scale are virtually all sent to dumps and landfills because of the lack of an acceptable recycling technology. However, the Bureau of Mines of the United States Department of the Interior, whose activities include conservation of mineral resources by the recovery of metal values from industrial wastes, developed a method for recovering over 80 % of the chromium and 90 % of the iron and nickel contained in pelletized mixtures of these stainless steel wastes. The Bureau's two-stage recovery technique relies on an initial reduction with carbon contained in the pellets, during meltdown in the arc furnace. This is followed by an addition of ferrosilicon to recover further chromium from the slag. The result is a master alloy suitable for recycling by charging to commercial stainless steel heats. In addition to offering a method for recovery of wasted critical metals, this procedure also helps to solve problems of storage and waste disposal, particularly of electric furnace bag house dusts. (Powell, 1975; Barnard, 1977)

Finally, after Grundtal Toilet roll holder is being used and disposed of, there are still five more steps needed to actually recycle the product, which are sorting, baling, shearing, media separation and melting. Most alloys are very similar in appearance. Sophisticated identification technologies, including X-ray spectrometry, are used to separate and prepare each type. Recycling stainless steel is a similar process to the one used for other ferrous metals:

-          Sorting: Because many forms of stainless steel are non-magnetic, this metal cannot be easily separated from other recyclables in a recycling facility with magnetic belts.

-          Baling: Stainless steel products are compacted into large blocks to improve ease of handling and transport.

-          Shearing: Hydraulic machinery capable of exerting enormous pressure is used to cut thick heavy stainless steel into smaller pieces.

-          Media separation: Shredders incorporate rotating magnetic drums to separate ferrous metals from other materials. Further separation is achieved using electrical currents, high-pressure air flow, and liquid floating systems.

-          Melting: The recovered materials are melted together in a furnace. This process is determined by the level of purity necessary for the future applications of the secondary raw material. The melted stainless steel is then poured into casters and shaped into ingots or slabs. Later on, they can be rolled into flat sheets that are used to manufacture new products. (BIR, 2016)

Conclusion:

After doing this research, it becomes clear to me that when we considering waste is not only about the finally disposed product, but also about every kind of waste and material coming out during the whole production chain. Also, in order to achieve sustainability, producers should pay attention not only to the recycling method associated with the end product, but to every step combined in the whole life cycle.

Bibliography:

Gary Coates, Technical Director, Nickel Institute and Dr. David Jenkinson, Director Nickel Institute Australasia. “What Is Stainless Steel?” Web. 11 Mar. 2016. <https://web.archive.org/web/20060924043735/http://www.nickelinstitute.org/index.cfm/ci_id/11021.htm>.

Weiss, N.L., (editor). 1985. SME Mineral Processing Handbook, Volumes 1 and 2. Society of Mining Engineers of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. New York, New York.

Van Ness, M., (editor). 1980. Proceedings of the 7th. Mineral Waste Utilization Symposium. Cosponsored by the U.S. DOI, Bureau of Mines and IIT Research Institute. Chicago, Illinois.

Guilbert, John M., and Charles F. Park, Jr. 1986. The Geology of Ore Deposits, W.H. Freeman and Company, New York, New York.

U.S. Environmental Protection Agency, Industrial Environmental Research Laboratory. 1976 (June). Metals Mining and Milling Process Profiles with Environmental Aspects. Prepared by Battelle Columbus Laboratories for U.S. Environmental Protection Agency. NTIS Publication No. 256394. Washington, D.C.

U.S. Environmental Protection Agency, Industrial Technology Division. 1985(b) (September). Guideline Manual for Iron and Steel Manufacturing Pretreatment Standards. Washington, D.C.

Aleshin, E., (editor). 1978. Proceedings of the 6th. Mineral Waste Utilization Symposium. Cosponsored by the U.S. Bureau of Mines and IIT Research Institute. Chicago, Illinois.

Technical Resource Document: Extraction and Beneficiation of Ores and Minerals. Washington, DC: U.S. Environmental Protection Agency, Office of Solid Waste, Special Waste Branch, 1994. Print.

H. E. Powell, W. M. Dressel and R. L. Crosby, Converting stainless steel furnace flue dusts and wastes to a recyclable alloy, Bu Mines RI 8039 (1975).

P. G. Barnard, W. M. Dressel and M. M. Fine, Arc furnace recycling of chromium-nickel from stainless steel wastes, Bu Mines RI 8218 (1977).

"- BIR - Bureau of International Recycling." - BIR - Bureau of International Recycling. Web. 12 Mar. 2016. <http://www.bir.org/industry/stainless-steel/>.