Partially Neutralized Sodium Salt of Bis Hexamethylene Triamine Penta (methylene phosphonic acid) BHMTPH•PN(Na2)

BHMTPH•PN( $\text{Na}_2$ ) — short for the partially neutralized sodium salt of Bis(Hexamethylene Triamine Penta(methylene phosphonic acid)) Boundary/Sodium Salt — is a high-performance aminophosphonate scale inhibitor designed for severe, high-stress water treatment environments.

By partially neutralizing the parent acid (BHMTPH or BHMT) with sodium hydroxide, it achieves a neutral-to-slightly-acidic pH range (~2.0–3.0 or ~4.0–6.0 depending on the exact neutralization grade), making it safer and much easier to transport, store, and formulate than the free acid form while maintaining extreme scale control efficiency.

Technical Specifications

Parameter	Specification
Chemical Name	Bis(hexamethylene triamine penta(methylene phosphonic acid)) sodium salt
Active Acid Content	$\ge 43.0\% - 50.0\%$
Active Salt Content	$\ge 50.0\% - 55.0\%$
pH (1% water solution)	2.0 – 3.0 (or 4.0 – 6.0 for multi-Na forms)
Total Phosphorus ( $\text{PO}_4^{3-}$ )	$\ge 15.0\%$
Fe Content	$\le 35\text{ ppm}$
Density (20°C)	$1.20 - 1.30\text{ g/cm}^3$

Key Performance Advantages

Unrivaled Calcium Sulfate ( $\text{CaSO}_4$ ) Inhibition:
- While common phosphonates like ATMP or HEDP excel primarily at $\text{CaCO}_3$ scale, BHMTPH derivatives are specifically engineered to prevent calcium sulfate and barium/strontium sulfate scale precipitation across a broad pH range.
High Calcium Tolerance:
- Standard phosphonates easily form insoluble “phosphonate-calcium” precipitates when hard water $\text{Ca}^{2+}$ levels are high. BHMTPH•PN( $\text{Na}_2$ ) has a much higher calcium tolerance threshold, meaning it stays dissolved and active even in extremely hard brine water.
Wide Temperature & pH Window:
- Its extended hexamethylene backbone structure provides superior thermal stability ( $>120^\circ\text{C}$ ), resisting thermal hydrolysis in deep wells and high-temperature heat exchangers.
Dual Corrosion & Scale Inhibition:
- Forms a thin, protective chelate film on metal surfaces, working as an effective cathodic/anodic corrosion inhibitor when combined with zinc salts or polymers.

Primary Applications

1. Oilfield Scale Control & EOR

Squeeze Treatments & Produced Water: Applied in oilfield injection water, downhole squeeze operations, and thermal enhanced oil recovery (EOR). It prevents severe $\text{BaSO}_4$ , $\text{SrSO}_4$ , and $\text{CaSO}_4$ scaling in high-salinity formation waters.

2. High-Stress Industrial Cooling Water

Used in heavy-duty open circulating cooling systems running under high cycles of concentration where both calcium carbonate and calcium sulfate limits are pushed to extreme thresholds.

3. Boiler & Desalination Plant Operations

Reverse Osmosis (RO) Antiscalant: Formulated into RO membrane antiscalant packages to protect membranes from gypsum ( $\text{CaSO}_4\cdot2\text{H}_2\text{O}$ ) fouling.
Evaporative Desalination: Prevents mineral encrustation in multi-effect distillation (MED) units.

4. Textile Processing & Detergents

Acts as a peroxide bleach stabilizer and chelating agent in fabric bleaching, binding trace metal contaminants ( $\text{Fe}, \text{Cu}, \text{Mn}$ ) to prevent fiber degradation.