IDEA #18PFDA Low-Toxicity Production Of Solderable Chromium-Plated Canned Food Steel Sheet

LOW(cid:2)(cid:2)TOXICITY PRODUCTION OOFF SOLDERABLE CHROMIUM(cid:2)(cid:2)PLATED CANNED FOOD STEEL SHEET APPLIED RESEARCH • MATERIALSAND PROCESS TECHNOLOGY • The production process does not require any capital expen(cid:2) diture and is applicable on the existing equipment. • The developed additives to the flux, chromium(cid:2)plated and passivating electrolytes are not expensive, readily available and low toxic. Areas ooff Application • Metallurgical industry: production of thin sheet and strip. • Canned food industry: manufacture of food cans. • Foodstuffs industry: production of canned food. • Light industry: manufacturing of packing tare. Economic Effectiveness It is known that more than 300 million of food cans are opened daily in the world, and the share of the tinned steel cans (as the main canned food tare) comprises 2/3 of the total amount of food cans. Let us assume that the quantity of the major tinned sheet producers in the world is about ten, and each producer will shift half of his production facilities to manufacturing of chromium(cid:2)plated steel sheet. In such case the production cost of one food storage can will be brought down by three cents due to the replacement of the tinned steel sheet by the chromium(cid:2)plated steel sheet. Then the economic effectiveness of the proposed new production technology for one company will reach more than 300 thousand USD per day or more than 100 million USD per year. Besides, not less than 20 m t of canned food steel sheet is annually produced in the world, while tinned steel sheet com(cid:2) prises about 2/3 of the total volume. Let us assume that the capacity of one tinned steel sheet producer approximately equals one tenth of the annual world volume, and half of this volume will be shifted by the producer to the output of chromi(cid:2) um(cid:2)plated steel sheet. It is known that the economic effect of producing 1 t of chromium(cid:2)plated steel sheet instead of tinned steel sheet is about 142 USD. Then the economic effect of the implementation of the new technology of producing chromi(cid:2) um(cid:2)plated steel sheet will amount per one producer about 100 million USD per year. Stage ooff Development Patenting of the inventions. Contact Details Organization: Ukrainian State University of Chemical Engineering Contact person: Prof. Oleg Girin Address: 8, Prospekt Gagarina, Dnipropetrovsk 49005, Ukraine Теl: (38 0562) 68 21 66/67 97 25 Fax: (38 0562) 33 71 36/47 33 16/67 97 25 E(cid:2)mail: girin@ua.fm DescriptionThe production of chromium(cid:2)plated canned food steel sheet instead of the tinned steel sheet (for packing of dry and gran(cid:2) ular foodstuffs) has been ceased in many countries due to the necessity of using in the production process of highly toxic hexavalent chromium compounds. According to the proposed production process, a thin (0.01(cid:2)0.03 μm) protective lustrous amorphous composite chromium coat is obtained using an electrolyte based on trivalent chromium compounds. Then the chromium(cid:2)plated steel sheet is passivated in a chromium(cid:2)free low(cid:2)toxicity electrolyte and soldered with tin solder during the manufacturing of cans. The basic production items are: • The developed chromium(cid:2)plating technology based on a sulfate(cid:2)acetate compound of trivalent chromium. • The developed chromium(cid:2)plating technology based on a sulfate(cid:2)formiate compound of trivalent chromium. These technologies are alternative, interchangeable and pro(cid:2) vides formation on the canned food steel sheet of amorphous coats. Forming of an amorphous structure in chromium coats leads to an increase of their protective properties while main(cid:2) taining the adhesive strength and plasticity characteristics. This ensures an adequate corrosion resistance of the passi(cid:2) vated chromium(cid:2)plated steel sheet (coat thickness 0,01(cid:2)0,03 μm ) in various model and foodstuff media, as well as a suffi(cid:2) cient level of its mechanical durability in the production of food cans. • The developed passivating technology that provides form(cid:2) ing on the chromium(cid:2)plated steel sheet of a colorless protec(cid:2) tive film during 2(cid:2)3 seconds. • The developed technology for soldering chromium(cid:2)plated steel sheet using tin base solder. The basis of this technology is the developed flux whose usage for soldering chromium(cid:2) plated steel sheet enable to upgrade the solder spread coeffi(cid:2) cient to 2.5(cid:2)3.0 (the standard norm being not less than 1.0). Innovative Aspect and Main Advantages The proposed chromium(cid:2)plated canned food steel sheet pro(cid:2) duction process is based on four potential inventions that are grounded on the usage of the phenomenon of the structure formation in the metallic materials being electrochemically deposited via a metallic liquid. These inventions are com(cid:2) prised of the development of electrolytes and methods of elec(cid:2) trochemical treatment of steel sheet and are aimed at reduc(cid:2) ing the canned food steel sheet production cost while replac(cid:2) ing the process of its tinning by the chromium(cid:2)plating process. The major advantages ooff the new production technology:: • The replacement of the canned food steel sheet tinning process by the process of its chromium plating results in sav(cid:2) ing expensive and scarce tin. • Increased rate of chromium deposition onto the steel sheet to 0.01(cid:2)0.015 μm/s. • Elimination of highly toxic hexavalent chromium com(cid:2) pounds during the electrochemical deposition of the chromi(cid:2) um coat onto the steel sheet and its subsequent cathode pas(cid:2) sivation. • Soldering of chromium(cid:2)plated canned food steel sheet becomes commercially feasible. INNOVATIVETECHNOLOGY OPPORTUNITIES FROM THE STCU 181