CONCEPT ENGINEERING FOR THE FILTRATION OF
SEALING PUMP FEEDWATER (GLAND WATER)

ISSUE

A filtration system for treating the feed water of a pump sealing water system was put into operation. This system consists of a pre-filter equipped with a filter element (2000 microns) followed by a 40 micron in-line strainer. The water supply source of the system is the tailing pond located at the overflow of the residue park of an iron concentrator.

This system is inadequate since the 40 micron (μm) in-line strainer clogs after only a few minutes of operation. During a first mandate, STS Canada has demonstrated that the fineness of the particles was the main cause of the clogging of the in-line strainer. The client then mandated STS Canada to perform pre-concept engineering to identify the appropriate technologies that will ensure sealant and cooling water quality at all times and that would not affect the integrity of the system, nor the equipment.


TECHNOLOGICAL CHALLENGE

  • Very high flow rate (800 m³ / h) in an existing building

  • Material to filter in shape of clogging particules

  • Control bacterial growth without affecting the integrity of the equipment on this water circuit.


RECOMMENDED SOLUTION

STS Canada recommended keeping the 1/16th inch (2000 μm) filter element already in place to remove coarse particles from the tailing pond water. This pre-filter will serve as protection for downstream water treatment equipment. The chosen technology to treat a flow rate of  800 m3 / h and to obtain at the outlet a water containing suspended particles smaller than 40 microns, is the hydro-cyclone.

Moreover, since the tailing pond's water is heavily loaded with bacteria (more than 1500 CFU / mL), it is necessary to control the bacterial population to prevent biofilm formation that could adversely affect particle capture efficiency and scale up the biofilm growth network. To do this, STS recommended installing a chlorine dioxide generator upstream of the hydro-cyclone to protect it from microbial corrosion and scaling.

RESULTS

In the end, STS Canada recommended the installation of a bank of 24 hydro-cyclones, of which 20 units will be in operation and 4 pending, which will provide an overflow at the outlet of the hydro-cyclone with particles whose size is less than 30 microns and a low bacterial concentration (less than 60 CFU / mL), to feed a pump sealing and cooling system.

INDUSTRY

Mines and Foundries

KEY TERMS

Iron-ore

Pump sealing water system

Filtration and water treatment

LEVEL OF INTERVENTION

Concept engineering of technologies

ESTIMATED COST

52000$

YEAR

2013