Belcor^® 590 corrosion inhibitor

General Product Information
Belcor 590 has been developed as an all organic closed system corrosion inhibitor for mild steel in industrial water systems.

The active ingredient of Belcor 590 is a polycarboxylic acid. The CAS number is 80584-91-4.

Typical physical properties
appearance		white, water-containing wet cake
active ingredient content		minimum 49% w/w
density		0.7 g/cm2
pH (10 % suspension)		about 5
solubility in
water		below pH 7.5 only very slightly miscible above pH 7.5 completely miscible
methanol		only slightly soluble (600 mg/l at 25°C)
pH limitations		good hydrolytic stability in acid/alkaline media.

Chemical reactivity
Belcor 590 contains a small amount of a biostat to prevent fungal and bacterial degradation.

Thermal stability
Belcor 590 has good thermal stability and is not degraded by UV light.

Logistics
classification		non-hazardous for supply non-hazardous for conveyance
packaging		70 kg (net) plastic drums

Toxicology data
acute oral LD50 (rats)		>5000 mg/kg
skin irritation (rabbits)		non irritant
eye irritation (rabbits)		non irritant
toxicity to fish
96-hr LC50 (zebra fish)		>1000 mg/l

Further details on safety and handling are available in the materials safety data sheet on this product.

Formulations based on sodium nitrite have been used for many years for the control of ferrous metal corrosion in closed cooling systems. Nitrite, like many other traditional corrosion inhibitors, is now considered environmentally unacceptable in many parts of the world.

Nitrite-free formulations utilising Belcor 590 corrosion inhibitor give good corrosion control under dosed recirculating water conditions, for example systems with long half-lives and high temperatures, such as central heating and air conditioning systems, with no detrimental effect on the environment.

Belcor 590 is a 49% w/w (min) wet cake of a substituted triazine. it is an organic anodic corrosion inhibitor which has proved useful as a building block for environmentally acceptable water treatment formulations. It can be used alone or together with Belcor 575 for an effective synergistic combination. The treatment option adopted depends on the water chemistry, as well as to the type of metal needing protection. Mufti-metal protection can be provided in combination with co-corrosion inhibitors such as TTA for copper and sodium molybdate for aluminium.

Figure 1: Comparison between Belcor 590 and nitrite at 80°C in water containing 150 mg/l calcium

Figure 1 shows the results from an accelerated bench top screening test. In this relatively aggressive test water (150 mg/l calcium. high sulphate and chloride levels) at 80°C, Belcor 590 has the same excellent corrosion control at a dose level of 400 mg/l as nitrite dosed at 1000 mg/l.

The dose level of Belcor 590 depends on the water chemistry with respect to calcium concentration and chloride/sulphate concentration. Under typical closed cooling system conditions, where hardness is < 150mg/l (as CaCO₃) and total dissolved solids are < 1000 mg/l Belcor 590 is typically dosed at 100-800 mg/l (as product). Higher levels of dissolved solids can interfere with Belcor 590's anodic corrosion inhibition mechanism, so higher dosage rates may be required.

Where additional corrosion protection is required, such as in waters with high levels of aggressive anions, Belcor 590 can be formulated with Belcor 575 ( hydroxyphosphono acetic acid) to provide a synergistic anodic-cathodic combination. Typical dosage rates in a water with less than 150 mg/l calcium (as CaCO₃) and more than 250 mg/l chloride (as ion) would be 60 mg/l Belcor 575 and 400 mg/l Belcor 590 (as product).

Feature		Benefit
Organic mild steel corrosion inhibitor		Effective replacement for nitrite and metal based water treatment programmes used in closed cooling systems
Synergistic combination with Belcor 575		Cost effective replacement for molybdate-based water treatment programmes

Patents
FMC owns or is the licensee of patents and patent applications which may cover the products and/or uses described in this brochure.

Process Additives Division