Polyacrylamide (PAM) in Mining

Did you know? Mining is actually one of the oldest industries in China and even in the world, with a history dating back thousands of years. At the same time, it serves as the foundation of the entire national economy — whether it's agriculture, textiles, chemical production, steelmaking, machinery manufacturing, house building, railway construction, national defense, or even our daily food, clothing, and supplies — none of it can function without the support of the mining industry. What's even more impressive is that mining has quietly "crossed over" into high-tech fields like aerospace and information technology. It's fair to say that mining plays an irreplaceable role in the economic development of China and the world.

However, every coin has two sides. While we vigorously extract and utilize mineral resources, a large amount of mineral processing wastewater is also generated. If this wastewater is not properly treated, it can pollute rivers, damage ecosystems, and cause significant environmental trouble.

The wastewater discharged during the mineral processing operations is called mineral processing wastewater. You might wonder: how much water is needed to process one ton of ore? The answer is: 4 to 7 cubic meters for flotation, 20 to 26 cubic meters for gravity separation, about 23 to 27 cubic meters for flotation-magnetic combined methods, and 20 to 30 cubic meters for gravity-flotation combined methods. Some of this water is recycled, but most of it is discharged from the plant along with tailings in the form of slurry. Especially during the flotation stage, various reagents are added to "extract" the valuable components from the ore — including collectors, frothers, activators, depressants, dispersants, and so on. Add to that the metal ions, suspended solids, and decomposition products of these reagents that are already present in the water, and the result is a mixture containing many harmful substances — what we call mineral processing wastewater. So how much of this wastewater is there? According to statistics, China directly discharges as much as 1.2 to 1.5 billion tons of wastewater annually from mining and mineral processing alone! This accounts for about 30% of the total wastewater from the non-ferrous metals industry. If this water is discharged directly without treatment, it will seriously pollute rivers and soil. Therefore, a key concern today is: how can we prevent mineral processing wastewater from harming our farmland and crops?

The answer lies in solid-liquid separation — that is, how to quickly separate the solid tailings particles from the water. Once the solids are removed, the clean water can be recycled or discharged to meet standards. Achieving this requires a "super gripper" capable of capturing the countless tiny particles suspended in the water. This is where Sinofloc Polyacrylamide (PAM) becomes the "all-rounder" in the field of mineral processing, especially the partially hydrolyzed version (HPAM). The secret to its effectiveness lies in its molecular structure — the PAM molecule is a long chain adorned with many active "little hooks" (polar groups). When added to a mineral suspension, these "little hooks" simultaneously adsorb onto the surfaces of different mineral particles, like numerous bridges connecting dispersed fine particles, gathering them into large, heavy flocs that settle rapidly.

1."Molecular Bridge" — How Does SINOFLOC PAM "String" Particles Together?

The reason PAM can quickly clarify turbid slurry is not through "brute force," but through its molecular structure. Think of a PAM molecule as a long "rope" with countless "little hooks" hanging along its sides. When PAM is added to the slurry, these "little hooks" actively seek out solid particles in the vicinity — one hook grabs one particle, another hook grabs another particle. Thus, a single PAM molecular chain acts like a "molecular bridge," connecting tiny particles that would otherwise remain separate. As more and more particles get "strung" onto this chain, they aggregate into large, heavy flocs that sink rapidly to the bottom like stones.

This process is scientifically known as "adsorption bridging." It may sound a bit complex, but the principle is actually quite simple: PAM acts like a "social connector" that excels at bringing scattered "little friends" together. The "little hooks" that make all this happen are actually polar groups on the PAM molecule, such as amide groups (-CONH₂) and carboxyl groups (-COOH). It is their presence that gives PAM its remarkable ability to "bind almost anything together."

2. Anionic vs. Cationic — Why Does PAM Need to "Match" the Application?

PAM is not just "one" type of reagent, but a large family. Depending on the electrical charge carried on the molecular chain, it can be divided into three types: anionic, cationic, and non-ionic. Why such a detailed classification? Because different mineral particles carry different surface charges — just like magnets have positive and negative poles: like charges repel, opposite charges attract.

For example, in copper ore processing, the surface of waste rock minerals (such as quartz) carries a negative charge. If you use anionic PAM, which is also negatively charged, they will "repel" each other — the PAM won't "bother" with the quartz. However, the surface of copper minerals (such as chalcopyrite) carries a positive or neutral charge under specific conditions, allowing anionic PAM to easily "attach" to them. This is the secret of "selective flocculation" — making PAM only grab the valuable minerals while leaving the useless waste rock alone.

Conversely, when dealing with positively charged minerals or organic matter, cationic PAM may be required. So, choosing PAM is like choosing shoes — you need to know what the "foot" looks like to get the right fit. Using the wrong type means zero results.

3. Why Must We Use Flocculants?

Think about it: if you leave a glass of water mixed with sediment sitting still, what happens? The larger sand particles will quickly sink to the bottom, but what about those extremely fine dust particles? They seem almost bewitched, hovering around in the water, refusing to settle down for days. This process is called natural sedimentation.

This creates a major problem: in a mineral processing plant, if you rely solely on natural sedimentation, those stubborn fine particles will keep floating in the water. When you try to pump the water out or dewater the bottom sludge, these tiny particles will clog the machinery, making dewatering and filtration operations particularly inefficient.

That's where flocculants come in — like a "super recall order." They can "capture" those unruly, non-settling fine particles and bind them together into large clumps, causing them to sink rapidly. This way, the water becomes clear, and the operations run smoothly.

4. Why Is "Adding Just the Right Amount" and "Don't Stir Too Hard" So Important?

It's just like cooking — adding too much salt or too little salt both ruin the dish. The same principle applies to flocculants. More is not always better.

• Too little (underfed): It's like sending out too few soldiers — they can only capture a small portion of the particles, leaving most of them still disorganized. The result is naturally poor.

• Too much (overstuffed): This is interesting. The surface of each particle becomes tightly wrapped by the polymer, like putting on a thick layer of "isolation suit." As a result, although all the particles are "dressed," they can no longer hold hands with each other, making it impossible to cluster together and sink.

• Over-mixing (too aggressive): You've finally connected the particles using "polymer bridges." But then, if you use a powerful mixer that goes "whirrr" and stirs vigorously, the shear force generated acts like invisible scissors, cutting those hard-built "bridges" one by one. The consequence? The particles that just clustered together are dispersed again. This is called deflocculation.

To sum it up in one simple sentence: flocculants must be added in just the right amount, and mixing should be gentle — only then will the small particles obediently cluster together and sink down happily and quickly!

5. Settling Issues in Leaching Tanks

Despite technological advances, the physical problems of coarse particle settling and equipment blockage do not automatically disappear — especially when processing heavy, coarse-grained minerals.

Leaching tanks in gold mines: This is a "hard-hit area" for such problems. Literature records show that in some gold mines using pneumatic stirring leaching tanks to process gold-bearing concentrates, "tank settling" frequently occurs — coarse particles settle and accumulate at the bottom of the tank, leading to reduced stirring intensity, deteriorated slurry circulation, and significantly lower gold leaching rates.

Pipeline blockage in mine tailings water treatment: Another source from 2026 also mentions that in scenarios such as mine tailings water treatment, although conventional flocculants can aggregate suspended solids, they tend to cause floc agglomeration and increased material viscosity, which in turn blocks equipment and pipelines.

In response to this issue, Sinofloc's R&D team has specifically developed an improved product. This product is based on conventional PAM but features modified molecular structures with the addition of hydrophilic groups, achieving a dual function of "flocculation + viscosity reduction." Typically, an anionic high-molecular-weight PAM is selected, making it suitable for treating high-turbidity, high-sand-content wastewater.

Operation Key Points

6. Copper Ore and PAM: When "Mineral Hunter" Meets "Molecular Gripper"

Have you ever wondered how copper is "captured" from ore? After copper ore is crushed, the valuable copper mineral particles (such as chalcopyrite) are mixed together with useless waste rock (mainly quartz), forming a turbid "mineral soup" — containing both the valuable minerals we want and the gangue minerals we reject. At this point, picking out those fine copper particles is not something a sieve can accomplish — their particle size is often finer than flour, some even only a few microns (one micron equals one-thousandth of a millimeter), completely invisible to the naked eye!

This is where our protagonist, Sinofloc Polyacrylamide (PAM), steps onto the stage. It acts like a "molecular-level hunter,"专门 responsible for "sticking" those tiny copper particles together, forming large flocs that rapidly settle to the bottom, thereby achieving efficient separation of copper minerals from waste rock.

Choosing the "Hunter": Anionic PAM Wins

Sinofloc technicians have discovered that the "charge type" of PAM is critically important for the selective separation of copper minerals. A study published in 2024 in a leading journal in the field of colloid and surface science systematically compared the performance of two types of PAM — Anionic Polyacrylamide (APAM) and Cationic Polyacrylamide (CPAM) — in copper ore separation.

We added APAM and CPAM respectively to a mixed slurry containing chalcopyrite (the mineral we want) and quartz (the mineral we want to discard), and then observed which one was more "biased" — which one preferred to grab chalcopyrite rather than quartz.

The results showed:

APAM is a discerning "sorter." Because it carries a negative charge, and the waste rock mineral quartz also carries a strong negative charge, the two repel each other — "like charges repel" — so APAM is "not interested" in quartz. However, the surface properties of chalcopyrite are different. APAM can adsorb onto it through hydrogen bonding, a kind of "molecular handshake," and then, like numerous bridges, connect the dispersed chalcopyrite particles together.

In contrast, CPAM is an indiscriminate "confused catcher." Although it can also grab chalcopyrite, it is "too enthusiastic" — it grabs quartz as well, showing no selectivity, making its performance inferior to that of APAM.

Feedback from our Brazilian customers indicates that copper tailings contain 2:1 type layered silicate minerals (such as biotite and chlorite), which carry permanent negative charges. This has a significant impact on the selection of flocculants. The study suggests that for copper tailings, using a medium molecular weight acrylamide/sodium acrylate copolymer with an anionic charge density of approximately 28% yields the best results.

Real-World Data: Just How Effective Is APAM?

In a practical application at a domestic copper-molybdenum mine, the Sinofloc technical team worked with the client to find the optimal "formula" for APAM: molecular weight of 10 million, preparation concentration of 1.60‰, and a dosage of 25 grams per ton of slurry. Under alkaline conditions at pH 11, the settling performance was best.

Even more interesting is a study on flocculation sedimentation of copper tailings slurry that compared the effectiveness of three types of flocculants: traditional inorganic flocculant aluminum sulfate, inorganic polymer flocculant polyaluminum chloride (PAC), and organic flocculant anionic polyacrylamide (APAM). The results showed that at the same dosage, the flocculation performance ranked as follows: APAM > PAC > aluminum sulfate. This demonstrates that for fine-particle materials like copper tailings, organic polymer flocculants have a clear advantage over traditional inorganic flocculants.

The study also found that APAM undergoes both hydrogen bonding and chemical adsorption on the surface of copper minerals — it's as if the APAM molecule "reaches out a hand" and "firmly grasps" the surface of the copper mineral, and this "handshake" process is spontaneous, requiring no extra force. Molecular dynamics simulations even more intuitively show that APAM molecules tightly "lie flat" on the copper mineral surface, while water molecules are "squeezed" to the side — this is the secret to efficient flocculation!

What's even more interesting is that the study also found that when APAM is used in combination with inorganic flocculants (such as aluminum sulfate and PAC), the settling performance is better than when any one of them is used alone. This demonstrates that "teamwork" is often more effective than "going it alone."

7. Lithium Ore and PAM: The "Lifeline" for Fine-Grained Spodumene

With the proliferation of electric vehicles, lithium has become "white petroleum" — it is the core raw material for manufacturing power batteries. But did you know that extracting lithium from spodumene (the most commonly used lithium ore) presents a vexing problem? Fine-grained spodumene (with particle sizes smaller than 30 microns) is easily lost during the flotation process because its mass is too small to effectively "collide" with air bubbles, resulting in it being discarded along with the tailings. This is not only a waste of resources but also generates a large volume of tailings slurry — these fine, viscous muds can take days to settle naturally! PAM serves here as an "accelerator" and a "lifeline."

The "Can't Float" Dilemma of Fine-Grained Spodumene

The flotation recovery of spodumene has always been a technical challenge, especially for the fine-grained fraction. Conventional flotation methods have very low recovery efficiency for spodumene particles smaller than 30 microns, because the small particles have low mass and low inertia, resulting in an extremely low probability of collision with air bubbles. This leads to significant losses of valuable lithium resources in the tailings, wasting resources and increasing the burden of tailings treatment.

So here's the question: Since direct flotation of small particles doesn't work well, is there a way to make them "larger" before flotation? The answer is yes — this is the concept behind the selective flocculation-flotation combined process.

Calcium Ion "Activation" + APAM "Binding": The Golden Combination for Spodumene Flocculation

The Sinofloc research team discovered that adding calcium ions (Ca²⁺) to the slurry dramatically improves the situation — calcium ions selectively activate the surface of spodumene, making it more "sticky" and thereby enhancing its ability to adsorb flocculants and collectors.

Then, anionic polyacrylamide (APAM) is added. The APAM molecules act like "super glue," sticking the activated spodumene particles together one by one to form large flocs larger than 50 microns. These large flocs act like "super particles" — their weight increases, and their probability of colliding with air bubbles also greatly increases, naturally leading to higher flotation recovery rates. Meanwhile, gangue minerals such as quartz, which are not activated by calcium ions, are "ignored" by APAM and remain dispersed, thus achieving selective separation.

This combination strategy of "calcium activation + APAM flocculation" represents a milestone achievement for the recovery of micro-fine spodumene. Researchers claim that this method is scalable and sustainable, and is expected to become the new standard for lithium ore beneficiation.

Why Does APAM Alone Perform Poorly? — Characteristics of Lithium Tailings

Lithium tailings are very different from copper tailings. Lithium tailings often contain large amounts of clay minerals (such as kaolinite, illite, etc.). These clay minerals have enormous specific surface areas and unique charge characteristics, giving them a strong ability to adsorb PAM. If APAM is used alone, the APAM molecules may be "snatched away" by the clay minerals, rendering them unable to effectively act on the spodumene particles.

This explains why, in lithium tailings treatment, researchers often adopt a combined scheme of "inorganic flocculant + PAM" or the combination strategy of "calcium ion activation + APAM." The underlying concept is: first, use inorganic reagents (such as calcium ions, calcium oxide, polyaluminum chloride, etc.) to adjust the chemical environment of the slurry and compress the double electric layer on the particle surfaces, causing the particles to "destabilize" and begin to approach each other; then, use PAM to "bridge" the already-clustered particles together, forming large flocs.

This two-step approach of "activate first, then flocculate" or "coagulate first, then flocculate" is a classic strategy for treating fine, viscous materials like lithium tailings.

8. Silver Ore and PAM: The "Invisible Hero" of Precious Metal Recovery + "Precision Dosing"

Silver is a precious metal — it is not only used in jewelry, but is also an important raw material for the electronics industry and the photovoltaic industry (solar panels). The beneficiation of silver ore is naturally more "sophisticated." In silver ore flotation and tailings treatment, PAM also plays an important role, but there is one key word that must be remembered: precision dosing.

Classic Case from a Silver Company: The Miracle of 6-8 Grams per Ton

Experiments have found that when adding polyacrylamide as a flocculant to backfill slurry, only an extremely small amount is needed — 6 to 8 grams per ton of material (you read that correctly, just 6-8 grams, equivalent to a tiny pinch per ton) — to produce astonishing results:

This is the classic example of "four ounces moving a thousand pounds" in precious metal mining applications — using an extremely small amount to achieve a huge improvement in efficiency. The relationship between flocculant dosage and backfilling effectiveness is nonlinear. What does this mean? — More is not necessarily better; there is an "optimal point." Adding too little yields insufficient results, while adding too much can backfire.

Dosage Effect Study in a Lead-Zinc-Silver Mine

Another classic study on silver ore comes from a full-tailings settling test at a lead-zinc-silver mine. Our team discovered a very important pattern: as the APAM dosage increases, the settling velocity first increases and then decreases.

Specifically:

• 0 g/t (none): Natural settling, very slow

• 10 g/t (low dosage): Slight improvement, but the effect is not significant

• 20 g/t (optimal dosage): Settling velocity reaches its peak, best results

• 30 g/t (high dosage): Settling velocity begins to decrease

• 40 g/t (excessive): The effect is even worse than at low dosage

Why does this happen? In the accelerated free-settling zone, free "fine" tailings particles and excessive "entrapped water" (water trapped within the flocs) can affect the settling velocity. In the hindered-settling zone, excess flocculant leads to steric hindrance between particles (as if each particle has a repulsion field around it), causing them to repel each other and hinder settling.

This "first increase, then decrease" pattern is the "golden rule" of PAM application — there is an optimal dosage. For this lead-zinc-silver mine, the optimal dosage is 20 g/t; for the silver company's backfilling process, the optimal dosage is 6-8 g/t.

Why Is Silver Ore So "Particular" About Dosage?

There are several possible reasons why silver ore is so sensitive to PAM dosage:

• The silver content itself is extremely low: The grade of silver in ore is typically only tens to hundreds of grams per ton (0.00x%-0.0x%), making it a truly "trace" element. Adding too much PAM may cause other materials to flocculate as well, diluting the grade of the silver concentrate.

• Silver minerals often coexist with lead, zinc, etc.: Silver ore is often not a single silver mineral but is hosted in minerals such as galena and sphalerite. These minerals have different surface properties and different adsorption capacities for PAM, requiring precise control.

• Excess PAM brings negative effects: Excess PAM makes flocs "sticky," slowing down settling and causing problems in subsequent filtration and dewatering steps, even clogging pipelines.

The selection of PAM is directly related to the type of mineral, the properties of the slurry, and the target metal, rather than just the name. The application principle of PAM in silver ore beneficiation is similar to that in copper ore — both use selective flocculation to improve the recovery efficiency of precious metals — but silver ore demands higher precision in dosage.

Comparison of PAM Applications in Three Types of Minerals

9. Phosphate Ore Beneficiation and PAM: Helping the "Mother of Fertilizers" Escape the "Sludge Trap"

If you have ever grown flowers, you must have heard of "phosphate fertilizer" — without it, plants cannot produce brilliant flowers or plump fruits. And the "hometown" of phosphate fertilizer is phosphate ore. Phosphate ore is known as the "Mother of Fertilizers," with over 80% of the world's phosphate ore being used to produce chemical fertilizers, feeding more than half of the Earth's population.

Why Is Phosphate Ore Beneficiation So "Difficult"?

After phosphate ore is mined, it must first be ground into a fine powder, and then separated from waste rocks such as clay and quartz through flotation. This process generates a large amount of slurry — processing one ton of phosphate ore requires approximately 1.5 cubic meters of water. Here's the problem: after beneficiation, the water content in the remaining tailings (the discarded waste rock) can be as high as 90%! Imagine: a bucket of tailings — 90% of it is water, and only 10% is solid. If this "sludge water" is discharged directly into a tailings pond, it occupies a huge amount of land; if the dam collapses, it could cause a catastrophic environmental disaster. Even worse, in phosphate ore-producing regions such as Morocco, South Africa, and Yunnan, China, many places are already water-scarce, making such water waste particularly "extravagant."

So the question is: how can we quickly separate water from ore during the beneficiation process, recover the water for recycling, and ensure the waste residue is safely stacked?

The answer is our old friend — Polyacrylamide (PAM).

PAM's "Three Battlefields" in Phosphate Ore Beneficiation

In a phosphate ore beneficiation plant, PAM primarily appears in three stages: tailings dewatering, concentrate settling, and the cutting-edge application of selective flocculation.

First Battlefield: Tailings Dewatering — Water Recovery Rate Exceeds 84%

This is the most "hardcore" application of PAM in phosphate ore beneficiation. In 2024, a study systematically compared 14 different flocculents for treating fine phosphate tailings. The results were impressive:

Even more impressive, the turbidity of the supernatant after treatment dropped to below 4.4 NTU — the turbidity standard for household tap water is typically between 1-5 NTU. This means that water treated with PAM is almost as clear as tap water!

What this means: tailings water that originally took days to clarify naturally becomes clear within minutes after adding PAM. The recovered clean water can be directly sent back to the beneficiation plant for recycling, saving water resources and reducing environmental pollution.

Second Battlefield: Concentrate Settling — An "Accelerator" That Doubles Efficiency

After phosphate ore flotation, we obtain phosphate concentrate slurry — the valuable mineral portion we want. However, this concentrate slurry is also very "dilute," and sending it directly for filtration is slow and consumes a lot of electricity.

At a collophane ore beneficiation plant in Yunnan, technicians discovered a trick: adding anionic PAM to the concentrate slurry increased the settling velocity several times faster than without PAM.

How is this done specifically?

This means that with the same equipment, where only one load of concentrate could be processed before, now three loads can be handled. This is the essence of "four ounces moving a thousand pounds."

Third Battlefield: Selective Flocculation — "Recovering Treasure" from "Waste"

This is a more "advanced" application of PAM in phosphate ore beneficiation. A persistent headache in phosphate processing is that phosphate minerals are often "entangled" with waste rocks such as clay and quartz, especially fine particles (smaller than 0.1 mm). Conventional flotation struggles to separate them, and they end up being flushed into tailings ponds, wasted.

Scientists have developed a technique called "selective flocculation." Here's how it works:

• A. First, disperse: Add a dispersant (such as sodium silicate) to get all particles "in their places," preventing interference with each other.

• B. Then, "pick out": Add a special type of anionic PAM that only "recognizes" phosphate minerals, adsorbing onto their surfaces like a magnet.

• C. Bridge together: The long molecular chains of PAM "string" the phosphate particles together one by one, forming large flocs that sink.

• D. Separate: Impurities like clay remain floating above and can be easily decanted away.

How effective is this technology? In the phosphate mining region of Florida, USA, large quantities of fine phosphate particles used to be flushed into tailings ponds (locally called "clay settling ponds"). Now, with selective flocculation technology, 60-70% of that phosphate can be recovered, and the concentrate grade can be increased by 2-5 percentage points.

What Are the "Special Considerations" for Using PAM in Phosphate Ore Beneficiation?

Based on extensive research and practical applications, there are several "secret tips" for using PAM in phosphate ore beneficiation:

1) Choose anionic, not cationic. Whether from experiments on Yunnan phosphate concentrate or international journal studies on phosphate tailings, the results all point to the same conclusion: for phosphate slurry (typically alkaline or neutral), anionic polyacrylamide (APAM) works best. Cationic PAM tends to "stick" to clay, causing adverse effects.

2) Molecular weight should be "tall." The PAM used for phosphate beneficiation should ideally have a molecular weight greater than 8 million. Why? Because phosphate particles are very fine, requiring "long-armed" molecular chains to bridge the distances between particles and "grab" them together. A molecular weight that is too small is like having "short arms and legs" — unable to reach.

3) pH needs to be "adjusted." Many beginners fall into this trap. After flotation of collophane ore in Yunnan, the slurry pH is often as high as 9-10, strongly alkaline. Adding PAM directly under these conditions yields poor results. The correct approach is: first add concentrated sulfuric acid to adjust the pH to 7-8, then add PAM. This small step can significantly improve solid-liquid separation efficiency.

4) Dissolve thoroughly — no "clumping." PAM can only function effectively when fully dissolved. Incomplete dissolution leads to "clumping and agglomeration," like lumps of overcooked dough — wasting reagents and clogging pipelines. The correct method is: use a dedicated mixer, stir for 40-60 minutes, allowing the PAM powder to completely "dissolve."

10. The "Efficiency Accelerator" in Coal Mines

The essence of coal slurry treatment is to disrupt the double-layer stabilization system composed of coal and clay mineral particles. These particles carry a negative surface charge in water, with a Zeta potential typically between -30mV and -50mV. The electrostatic repulsion between particles is far greater than the van der Waals attraction, forming a colloidal dispersion system that does not settle for long periods. The role of polyacrylamide (PAM) is not to neutralize the charge — that is the task of inorganic coagulants such as polyaluminum chloride — but rather to achieve flocculation through the bridging adsorption of its long molecular chains. The carboxyl groups (-COO⁻) of anionic PAM form hydrogen bonds and hydrophobic associations with the hydrophobic regions on the coal particle surfaces. A single PAM chain with a molecular weight exceeding 10 million can simultaneously anchor dozens of particles, spanning the Debye shielding layer and converting electrostatic repulsion into mechanical connections. In industrial applications, PAM chains with a hydrolysis degree of 25%-35% fully extend under the pH 7-9 conditions typical of coal slurry. The optimal dosage is generally 3-8 g/m³. There are two key control parameters: first, the turbulence intensity in the initial mixing stage, where the velocity gradient G value must be maintained at 500-1000 s⁻¹ to ensure sufficient contact between PAM chains and particles without shearing the chains apart; second, during the flocculation stage, the G value is reduced to 20-50 s⁻¹ to protect the already formed flocs from being broken. After PAM treatment, the floc settling velocity increases from the natural settling rate of 0.01 m/h to 1-2 m/h, and the overflow turbidity drops from several thousand NTU to below 300 NTU, providing the technical prerequisite for closed-circuit circulation of coal slurry.

When we add HPAM to the flotation slurry, it acts like "super glue," quickly "sticking" fine coal slime particles together to form large flocs that rapidly settle to the bottom, greatly improving solid-liquid separation efficiency. The Sinofloc research team found that when treating coal slurry from a certain coal mine, using anionic polyacrylamide (APAM) yielded the best results. By adding approximately 90 grams of PAM per ton of coal slime, in combination with other reagents, they achieved an outstanding result: a clean coal ash content (impurity level) as low as 1.24%, with a recovery rate as high as 88.75%. This not only produces purer coal but also increases the coal mining rate while reducing energy consumption.

11. The "Classification Expert" in Hematite

The more remarkable ability of HPAM is "selective flocculation," which is its "signature move" in the field of mineral separation. Take the mixture of hematite and quartz as an example: the surface of hematite seems naturally inclined to like HPAM. The carboxyl groups and other functional groups on the HPAM molecular chain firmly "embrace" the hematite particles (through electrostatic adsorption and hydrogen bonding), linking them together one by one into a cluster that sinks to the bottom. Meanwhile, the surface of the adjacent quartz particles shows "no interest" in HPAM, remaining dispersed and suspended. In this way, the two originally mixed minerals are easily separated.

In the laboratory, scientists optimized the process conditions. In an alkaline environment at pH 10, by adding just 10 grams of modified polyacrylamide (HPM) per ton of ore, followed by a high-intensity magnetic separation process, the results were encouraging: compared with conventional methods, the recovery rate of iron concentrate was miraculously increased by 5.39%. This valuable iron was "rescued" and resource waste was avoided.

This "black technology" of selective separation using HPAM is attracting keen interest from researchers around the world. Everyone is striving to find the optimal process "formula," such as adjusting the molecular weight of PAM, the degree of hydrolysis, and the pH of the slurry, hoping to make the separation effect more significant and stable, bringing even greater surprises for the efficient utilization of mineral resources.

From copper ore to lithium ore, from silver ore to phosphate ore, and then to coal and hematite — Sinofloc Polyacrylamide works like a tireless "molecular magician,"shuttle in the world of slurry, stringing together those stubbornly suspended fine particles one by one, bundling them into clusters, and sending them to the bottom — turning turbidity into clarity and wastewater into a resource.

Don't underestimate this simple act of "stringing together" — behind it lies a major impact on the mining industry's bottom line: water recovery rates go up, energy consumption goes down; tailings ponds become safer, concentrate grades improve. Sinofloc's anionic, cationic, and non-ionic PAM products are each "tailor-made" for specific ores.

A beneficiation plant races against time every day, battles with equipment, and wrestles with water quality. What Sinofloc aims to do is to help every customer win this race with stable, efficient, and precise PAM products. Cleaner water, purer minerals, smoother processes — this is not just a slogan; it is a commitment rooted in every single molecular chain.