BLACK CHROMIUM PLATING BATH

PLANT PARAMETERS
Capacity, Sq.Mt PA 200
No.of Shifts / day 1
Working days / Yr 300
Land Area, m2 100
Covered Area, m2 75
MANPOWER
Managerial 1
Skilled 2
Unskilled 3
RAW MATERIAL
Chromium plating bath Additives
Other chemicals  
UTILITIES
( per Sq.Mt of Product)
Power, KwH 100
Process Water, KL 25
Raw water, KL 1.5
PLANT & MACHINERY
Silicon rectifier Rectifier
Chromium plating tank Resistance board
Anodic cleaning tank Etching tank
Water swill Polypropylene tubs
Black chromium plating bath is used for selective chromium coating. Flat plate or focusing type solar collectors require this type of selective coatings for efficient solar heat absorption . Black chromium coating has good corrosion resistance. In addition, this type of coating can be used on machinery parts such as certain parts of printing machinery, parts of optical instruments etc. which need coating to minimize reflection. Other applications include using solar energy for drying cereals in godowns, as an anti reflection coating on optical mounts and for decorative coatings on watches, jewelry, furnitures, etc.

The special requirements of a black chromium plating bath for solar collectors are :

  • The bath should be operated at room temperature
  • The plating current density should be low
  • The coating should be uniform
  • The bath should have good shelf life
  • The bath should have good working life
  • The coating should have high absorptance in the visible region of solar radiation.
  • The coating should have low emittance in the infrared region
  • The bath should have high tolerance to impurities
  • The bath should have simple regeneration and replenishment procedure
  • The coating should have good corrosion resistance
  • The coating should have high thermal stability
  • The bath should have high stability above room temperature.

PROCESS

The process being offered in this proposal uses a bath which contains special additives and fulfills all the above requirements. Water temperature in solar plate collectors coated in this bath can rise above 800 C after about six hours of sunshine. The black chromium coating bath is stable upto 3500 C and can therefore be used for collectors operating upto 3000 C .

A variety of substrates for example; mild steel, copper, aluminium, galvanized iron etc. have been successfully coated with black chrome. The shelf life of the bath has been tested for a period of 6 years and no signs of deterioration has been noticed. The coating has been successfully applied on components of optical instruments, watch cases etc.

NRDC

National Research Development Corporation, a Government of India Enterprise, is a premier technology transfer Corporation with four decades of experience. It has helped establish over one thousand projects in the small and medium scale sector. The supply of technologies and services to entrepreneurs extend both in the developing and developed countries like USA, Germany, Malaysia , Burma , Nepal, Senegal, Madagascar, Indonesia Philippines, Vietnam, Lanka, Kenya, Brazil, Bangladesh and Egypt.

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Services offered by NRDC


NATIONAL RESEARCH DEVELOPMENT  CORPORATION
(A Government of India Enterprise)
20-22, Zamroodpur Community Centre,
Kailash Colony Extension, New Delhi-110 048. (INDIA)
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