I. Process Background
The core hydrometallurgical processes in nonferrous metal concentrators (copper, lead, zinc, nickel, molybdenum, tungsten, etc.) comprise crushing, grinding, classification, flotation, thickening, and filtration. At each stage, slurry density (or solid–liquid ratio) is a critical control variable: the discharge density from the mill governs the grinding circuit load, directly affecting mill energy consumption and liner life; the feed density to hydrocyclones determines the classification particle size, thereby influencing subsequent flotation efficiency; the feed concentration to flotation cells dictates reagent performance, which in turn impacts metal recovery; and the underflow density from thickeners sets the concentrate/tailings discharge consistency, crucial for the stability of filtration, press filtration, and tailings conveyance.
According to long-term statistics from China’s mineral processing industry, for every 1 percentage point deviation of slurry concentration from the setpoint, metal recovery can drop by 0.3% to 0.5%, while grinding energy consumption may increase by 1% to 3%. For a large concentrator handling 5 million tons of raw ore annually, the cumulative economic loss due to concentration fluctuations over a year can amount to several million yuan or more.
II. Pain Points of Traditional Density Measurement Solutions
• Gamma-ray concentration meters: While highly accurate, they are radiation-based instruments requiring a Radiation Safety License, annual inspections, training for radiological workers, and costly source decommissioning. Several major mining provinces have already placed them on restricted-use lists, making environmental approval increasingly difficult for new projects.
• Differential-pressure or diaphragm-type concentration meters: Directly exposed to highly abrasive metallic slurries—especially those containing high-density minerals such as iron ore and copper ore—the diaphragms suffer severe wear, exhibiting noticeable zero-point drift after just 3 to 6 months of operation and necessitating frequent shutdowns for calibration. Scale buildup on the diaphragm surface further amplifies measurement errors.
• Tuning-fork or vibratory concentration meters: In flotation feed lines, surfactants generate abundant fine froth that severely disrupts the fork’s vibration frequency, causing erratic, fluctuating readings and precluding stable process control.
• Underflows from thickeners often reach concentrations of 50% to 70% and frequently contain coarse particles; conventional insertion-type instruments become clogged with alarming frequency, resulting in high maintenance demands and low availability.
III. PS7000 Solution
Typical deployment of the PS7000 in concentrators covers three key measurement points: mill discharge/hydrocyclone feed (to control the grinding circuit), flotation feed (to stabilize flotation concentration), and thickener underflow (to regulate discharge consistency). The instrument is installed via flanged direct insertion; ultrasonic waves are transmitted from outside the pipe, and the echo is analyzed for acoustic impedance features, ensuring no contact with the slurry and eliminating wear and fouling concerns.
Figure 1: Schematic layout of three slurry density measurement points in a nonferrous metal concentrator
Core Value of the PS7000 in the Nonferrous Metallurgy Industry ▸ The Chirp algorithm’s broadband analysis ensures stable measurement even for flotation feed containing fine bubbles, eliminating the “jumping” issue common with tuning‑fork‑type instruments; ▸ A 316L–ceramic probe assembly (with a 2205 duplex steel option) delivers exceptional resistance to highly abrasive metal slurries, offering a service life of at least 5 years; ▸ Flange‑mounted, direct‑insertion installation covers pipe diameters from DN50 to DN1000, providing a one‑stop solution for grinding, flotation, and thickener piping requirements; ▸ Completely non‑nuclear—zero radiation—no radiation permit required, ensuring smooth environmental compliance approval; ▸ Dual 4–20 mA outputs plus MODBUS‑RTU protocol enable seamless integration with the plant’s DCS/PLC automation system. |
IV. Customer Value
Comparison Dimensions | Original gamma-ray/differential pressure solution | PS7000 Solution |
Operational Safety | Radiation source control faces significant pressure | Intrinsically safe · Radiation-free |
Instrument service life | Diaphragm wear—maintenance required every 3 to 6 months | Ceramic probe with ≥ 5 years of maintenance-free operation |
Stability of Flotation Feed Measurement | Foam interference · Data jumps | Chirp anti-bubble · Stable output |
Risk of underflow blockage | Insertion-type instruments frequently experience pipe blockages | Non-contact · Completely clog-free |
Metal recovery rate | Concentration fluctuations lead to a decline in the recovery rate | Precision concentration control · Steady improvement in recovery rate |
At a large iron ore concentrator in Xinjiang, the PS7000 replaced the original differential-pressure concentration meter on the mill discharge line. Extensive on-site comparisons confirmed that its output fully matched results from manual sampling and laboratory analysis, with stable accuracy over extended operation, making it a standard fixture at this plant. Similar applications have been successfully deployed at a nonferrous metal concentrator in Qinghai and a copper–molybdenum mine in Inner Mongolia, among other projects.
