Co-processing : A sustainable solution for SPL management Holcim Technology 2014 Ltd

Transcription

1 Co-processing : A sustainable solution for SPL management 2014 Holcim Technology 2014 Ltd

2 Business cells from market perspective defined Geocycle has access to 14 facilities across India, co-processing the waste in ACC and Ambuja Cement kilns The wide spread presence across the country gives the flexibility to provide seamless solutions across the country

3 Aluminum Production Electrolytic reaction conducted in series of cells/pots Operating temperatures of C kAmps Produce 1-3MT/pot/ day Pot last 4-8 yrs Refractory brick or insulation material (alumina) Cathode block made from anthracite and/or graphite mixed with pitch and baked at high temperatures Rammed anthracite paste Sidewall brick - anthracite, graphite, SiC or SiC/anthracite blocks

4 Spent Pot Liner (SPL) Spent Pot Liner (SPL) is a waste from the smelting operation in the Aluminum Industry. SPL is generated when a pot fails Spent lining must be removed and replaced SPL is considered to be a hazardous waste because it contains significant quantities of absorbed fluorides along with traces of cyanide. The waste consists of 2 parts viz. first cut (carbon cathode) and second cut (refractory) SPL typically contains 60% by weight of carbon and 40% by weight of refractory portion Specific generation of SPL is 15 Kg/Ton of Aluminium produced

5 Conventional Options of SPL management Secured Storage, Land filling (SLF) and incineration As per CREP recommendation SPL is being stored in isolated and covered sheds Huge area requirement and capital investment As per HWM Rules, 2008 the conventional methods of SPL disposal are Land filling or SLF for refractory portion Incineration for carbon portion (as CV> 2500 Kcal/Kg) Some of the smelter plants such as NALCO has SLF Life less than 5 years and Huge area requirement None of the smelter plants have captive incinerator Orissa and Chhattisgarh produces 80% of Aluminium in India and none of these states have incineration facility Thus this waste is getting dumped and stored on site for years together, posing huge environmental and health risk to society around. Unsound SPL management is a risk to the environment, in particular to the ground water and the health of people.

6 How cement plant can act as a partner It is important to note that SPL can be safely handled ensuring that the associated hazards of SPL are well mitigate through adequate feeding and storage installation at the plant. Cement Plant can help in handling SPL in a safe way Handling system through dedicated arrangement of waste handling with proper dosing system. The SPL needs to be processed into requisite size and characteristics for safe handling of SPL in the cement plant. The high temperature and long residence time condition of the cement kiln, the SPL would be safely destroyed while recovering the energy and materials value from the waste. PPEs needed:, full body disposal Tyvac suits with hood, Full face cartridge mask, cut resistant gloves, nitrile gloves, helmet and safety suits Personal monitoring equipment for HCN ACC and Ambuja cement limited with technical expertise for Holcim has set up safe handling waste management facility. 6

7 Holcim Plants Co-processing SPL Independent pre-treatment of SPL has been demonstrated in several ways. The only successful and commercialized treatment option is currently offered by Regain in Australia Holcim Plants using untreated SPL: Australia, New Zealand, South-Africa, Canada, France and Brazil. Cement Australia Railton Plant, Tasmania co-processing SPL (size 5-10 mm) in calciner from Rio Tinto Aluminium, Bell Bay Smelter Capacity of Railton Cement Plant is 1 MTPA Capacity of Bell Bay Smelter is 0.2 MTPA SPL Generated is 2500 TPA Gladstone Plant, Queensland co-processing calcined SPL (size microns) in main burner from Boyne Smelters. Capacity of Gladstone Cement Plant is 1.6 MTPA Capacity of Bell Bay Smelter is 0.5 MTPA SPL Generated is 8000 TPA Holcim Brazil. Holcim Brazil co-process 1.0 TPH of SPL from 3 aluminium smelters directly in the pre heater (riser duct) with the granulometry of < 50mm. Feed rate limited by F which impacts setting time of cement 7

8 Safe handling - storage installations SPL storage elevated location roll gate closes automatically gutter below gate prevents water ingress safety rules listed at entry 2013 Holcim Ltd.

9 Safe handling - storage installations SPL storage ventilation all around 2013 Holcim Ltd.

10 Safe handling - storage installations SPL storage ventilation by longitudinal openings in the roof with cover from outside to let air/gas go out but prevent rain water coming in 2013 Holcim Ltd.

11 Safe handling - storage installations Bunding inside all around captures potentially penetrating water and prevents contact with stored SPL 2013 Holcim Ltd.

12 SPL generation in India There are 3 major companies in India who is in to Aluminium smelting business. The table illustrates the existing aluminium smelting plants with the capacities from where SPL will be generated as waste. SPL generation annually from these units is calculated as approx. 48,907 T. additionally all these units have historical storage of these materials for many years amounting to thousands of tons. 12

13 Current Status India MoU with Vedanta for conducting SPL trial at ACL Bhatapara CPCB protocol for emission monitoring to be followed. Trial to be conducted with highest standard for safety ACL Bhatapara has enclosed installation to ensure safe handing of SPL Detailed risk assessment undertaken with Holcim experts before the trial Crusher vendor developed for ensuring crushing of SPL at Balco site, close to 1000T crushed for trial purpose. 13

14 ACL Bhatapara: dedicated waste handling facility MMO Building Light Material Feeding Shed Platform Building Conveyor Gallery for Light Material and MMO USS Building Cable Gallery Water Storage Tank and Pump House

15 ATS Feeding system

16 Over head crane Feed hopper Weigh feeder Storage area Belt conveyer

17 For a zero-waste future

18 Process flow Diagram