In the waste lithium battery recycling industry chain, "black powder" is a highly valuable core intermediate product. Its composition and recycling process directly determine the efficiency and economic viability of battery resource recycling and are crucial for reducing environmental pollution.

I. Definition and Source of Black Powder
"Black powder" in battery recycling, formally known as "waste lithium battery positive electrode active material powder," primarily originates from the disassembly and sorting of waste lithium-ion batteries (such as ternary lithium batteries and lithium iron phosphate batteries). After waste batteries undergo discharge, casing removal, electrolyte removal, and separation of the negative electrode copper foil and positive electrode aluminum foil, the black powder that falls off the surface of the positive electrode aluminum foil through physical or high-temperature stripping processes is commonly referred to as "black powder" in the recycling industry. This powder accounts for approximately 30%-40% of the total weight of waste lithium batteries and is the primary carrier of precious metals and key metal elements in batteries.
II. Black Powder Core Components
The composition of black powder varies significantly depending on the type of primary battery and can be primarily divided into two categories:

Ternary lithium battery black powder: The core components are nickel (Ni, typically 15%-30%), cobalt (Co, 5%-12%), manganese (Mn, 5%-15%), and lithium (Li, 2%-5%). It also contains small amounts of aluminum (from the cathode current collector residue), carbon (as a conductive agent), and impurities.

Lithium iron phosphate battery black powder: The main components are iron (Fe, 20%-30%), phosphorus (P, 10%-15%), and lithium (Li, 2%-4%). It does not contain precious metals such as cobalt and nickel, and impurities are primarily aluminum and carbon.

The compositional differences between the two types of black powder directly determine their recycling technology routes and economic value. Ternary black powder, due to its cobalt and nickel content, offers greater recycling profit margins and is currently the focus of the industry. Lithium iron phosphate battery black powder, on the other hand, requires scaled-up recycling to reduce recycling costs and focus on the recycling of lithium and iron.
III. Mainstream Black Powder Recovery Processes
Currently, the industry's black powder recovery is primarily categorized into three major technical routes: pyrometallurgy, hydrometallurgy, and dry recovery, each with its own advantages and disadvantages:

Pyrometallurgy (High-Temperature Smelting)

Principle: Black powder is mixed with auxiliary materials such as coke and limestone and smelted at 1200-1500°C. Redox reactions transform the metal elements into alloys (such as nickel-cobalt alloys), while lithium enters the slag for separate extraction.

Advantages: Mature process, large processing capacity, strong adaptability to raw materials, and capable of processing black powders with complex compositions.

Disadvantages: High energy consumption (approximately 3000-5000 kWh per ton of black powder), low metal recovery rates (cobalt and nickel recovery rates are approximately 85%-90%, while lithium recovery rates are only 50%-60%), and flue gas pollution. Hydrometallurgy (Chemical Dissolution)
Principle: Black powder is dissolved in an acidic solution such as sulfuric acid or hydrochloric acid. By adjusting the pH and adding extractants, metal ions such as lithium, cobalt, nickel, and manganese are sequentially separated, ultimately producing battery-grade raw materials such as lithium carbonate, cobalt sulfate, and nickel sulfate.

Advantages: High metal recovery rate (cobalt, nickel, and lithium recovery rates can reach over 95%), high product purity (meeting the requirements for power battery cathode materials), and low energy consumption.

Disadvantages: Lengthy process (requiring 10-15 steps), generation of acidic wastewater and waste residue, requiring stringent environmental protection treatment facilities and significant initial equipment investment. Dry Recovery (Physical Separation)
Principle: Low-temperature calcination removes carbon and binders from black powder. High-voltage electrostatic separation, magnetic separation, and other physical methods are then used to separate different metal oxides (such as lithium compounds and nickel-cobalt-manganese oxides).
Advantages: No wastewater or gas is generated, the process is short (3-5 steps), and energy consumption is only one-third of that of pyrometallurgy, making it an environmentally friendly process.
Disadvantages: The technology is not yet fully mature, and requires high-quality black powder pretreatment (strict impurity removal). Currently, it is only applicable to certain high-purity black powders, and large-scale application still requires breakthroughs.

IV. The Significance of Black Powder Recycling and Current Industry Status

Resource Recycling Value: Global cobalt and nickel reserves are limited (cobalt reserves are only approximately 7 million tons), and my country's external dependence exceeds 90%. Black powder recycling can achieve "urban mining" resource utilization—for every 10,000 tons of recycled ternary lithium battery black powder, approximately 1,000 tons of nickel, 500 tons of cobalt, and 300 tons of lithium can be extracted, equivalent to reducing 100,000 tons of raw ore mining.

Environmental and Emission Reduction Significance: If black powder is discarded carelessly, heavy metals such as cobalt and nickel in it may seep into the soil and groundwater, causing long-term pollution. Recycling and treatment can increase the harmlessness rate of heavy metals to over 99%, while also reducing the emission of pollutants such as dioxins from battery incineration.

Current Industry Development Status: Currently, wet processing is the main method for black powder recycling in my country (accounting for approximately 70%), leading companies such as GEM and Huayou Cobalt have already implemented 10,000-ton wet recycling production lines. Pyrometallurgical processes are primarily used to process low-grade black powder or overseas black powder with high cobalt content. Dry processes are in the pilot stage, with some companies having built 1,000-ton demonstration lines and expected to gradually scale up over the next 3-5 years.

V. Future Development Directions

With the onset of a wave of retired power batteries (my country's retired battery volume is expected to exceed 1 million tons by 2025), black powder recovery will evolve towards "low energy consumption, high purity, and full component recovery." On the one hand, wet processes will reduce costs through new extraction agents and automated control; on the other hand, dry processes will achieve breakthroughs in impurity separation technology, achieving "wastewater-free" recovery. Furthermore, for lithium iron phosphate battery black powder, lithium-iron-phosphorus synergistic recovery technologies will be developed to enhance its economic value and promote the resource utilization of all types of battery black powder.