Liaoning Xinda Talc Group Co., Ltd. — Cao Xinyu. 

First Part: We previously analyzed four potential mechanisms for energy conservation in talc pulping. This article leverages comprehensive experimental research and industrial pilot-scale trials conducted by Xinda Talc Group to validate these mechanisms through real-world data, while assessing their industrial application value, challenges, and future development directions.

Ⅳ. Research and Practice of Liaoning Xinda Talc Group   

Leveraging its high-quality talc resources and advanced powder processing technology, Xinda Talc Group conducted a series of laboratory pilot tests and industrial-scale pilot studies based on the aforementioned mechanism hypothesis. These efforts aimed to validate the practical effectiveness of talc powder in reducing grinding energy consumption and to explore its underlying mechanisms.

4.1 Experimental Materials and Methods 

Raw Materials: Three paper-grade talc powders of different specifications produced by Xinda Talc Group were selected: SD9043-A (median diameter D50=10μm, well-structured flake morphology), SD9043-B (median diameter D50=5.0μm, moderate flaking degree), and SD9043-C (median diameter D50=10μm, surface-modified). The control group consisted of commercially available ordinary heavy calcium carbonate (GCC, median diameter D50=10μm) and a blank group without filler. All experimental slurries were prepared as chemical mechanical pulps by mixing bleached sulfate coniferous wood pulp (NBKP) and bleached sulfate broadleaf wood pulp (LBKP) in a 7:3 ratio. Methods: Laboratory Pulping Experiment: Using a PFI mill (or standard laboratory pulping machine), under fixed pulp concentration (10%) and rotational speed (e.g., 10,000 rpm), different types and proportions of talc powders (mass percentages relative to dry pulp: 0%,5%,10%,15%) were added. Pulping degree (SR, a key indicator of pulp water filtration performance), fiber length distribution (FQA analysis), and unit pulping energy consumption were measured before and after pulping.

Energy consumption monitoring and analysis: Accurately records current, voltage, and time during the grinding process to calculate actual electrical energy consumption. Thermal imaging cameras are employed to monitor surface temperature variations of the grinding disc, indirectly reflecting ineffective energy consumption.

Fiber morphology observation: The surface morphology of fibers, degree of fibrillation, and distribution state of talc powder were observed using scanning electron microscopy (SEM) after adding different fillers.

Pilot-scale industrialization: A pilot test was conducted on a twin-disc pulping mill at a cooperative paper mill with a processing capacity of 5-10 t/d, investigating the effects of talcum powder on energy consumption, pulp quality, and subsequent papermaking performance during continuous production.

4.2 Experimental Results and Analysis of Grinding

 Energy Consumption Patterns: Laboratory results demonstrate that moderate addition of Xinda Talc Group SD9043-A talc powder (5%-10%) significantly reduces slurry grinding energy consumption compared to untreated samples, with maximum reductions reaching 5%-12%. SD9043-B exhibits slightly inferior energy-saving effects (5%-7%) due to its poor flake morphology. SD9043-C, after surface modification, shows improved dispersibility and enhanced fiber compatibility, achieving comparable energy-saving performance to SD9043-A while maintaining effectiveness even at high addition levels (15%). In contrast, unmodified fine powders tend to aggregate, resulting in minor energy consumption increases or "consumption escalation" phenomena. Heavy calcium carbonate (GCC, median diameter D50=10μm) shows negligible or slight energy consumption changes (+2%-3%) under equivalent addition conditions, likely attributable to its angular morphology and higher hardness [3].

Pulp quality and fiber morphology: The slurry samples containing talc powder exhibited pulp strength comparable to or slightly higher than the control group, while demonstrating significantly lower average fiber length loss rates and a higher proportion of long fibers. SEM observations revealed well-developed surface fibrillation in talc-added fibers, with talc flakes primarily adhering to fiber surfaces or filling interstitial spaces within the fiber network, showing no significant fiber fragmentation. These findings indicate that talc incorporation reduces ineffective fiber cutting and preserves fiber length under similar pulp strength conditions, consistent with the "stress dispersion and buffering" mechanism.

Pilot-scale industrialization results: During pilot production, continuous addition of 10% SD9043-A talc powder reduced the motor current of the twin-disc slurry mill by approximately 6.5% on average, while lowering power consumption per ton of pulp by about 5.8 kWh/t. Concurrently, the filtered water performance of the pulped slurry improved. The subsequently produced cultural paper maintained original strength specifications while exhibiting slight enhancements in opacity and whiteness, increased bulk density, and excellent printing adaptability.

4.3 Preliminary Validation of Mechanisms 

Based on experimental results, Xinda Talc Group's research indicates that the "lubrication and isolation" effect and "stress dispersion and buffering" effect of talc powder serve as the primary mechanisms for reducing grinding energy consumption. The lubricating properties of flake talc powder minimize frictional heat generation and ineffective work, while its low hardness characteristics effectively protect fibers, reducing energy loss caused by excessive fiber cutting and damage. Surface-modified talc powder (SD9043-C) further enhances lubrication and buffering performance by improving interfacial bonding with fibers, enabling significant energy savings even at higher dosage levels.

Ⅴ. Industrial Application Prospects and Challenges of Talcum Powder for Reducing Grinding Energy Consumption 

5.1 Promising Application 

Outcomes with Significant Direct Economic Benefits: Pulping is the primary energy-consuming process in paper mills. Even a 5%-10% reduction in grinding energy consumption can result in annual electricity savings of hundreds of thousands to millions of yuan for medium-sized paper mills.

Enhancing paper quality and production efficiency: While reducing energy consumption, talc powder can also improve certain critical properties of the finished paper, such as bulk density, opacity, and printing suitability, thereby assisting enterprises in developing high-value-added products.

Aligned with green manufacturing and sustainable development strategies: Reducing energy consumption translates to decreased carbon emissions, meeting the current national "dual carbon" targets for energy conservation and emission reduction in manufacturing sectors, while enhancing corporate social responsibility and green image.

Expanding the application value of talc powder in the papermaking industry: Elevating talc powder from a mere 'filler' to a 'functional additive/energy-saving material' can help consolidate and expand its market share in the papermaking sector.

5.2 Challenges in Determining 

Optimal Additive Dosage and Formulation: The energy-saving efficacy of talcum powder is influenced by multiple factors including its inherent properties (particle size, flake shape, hardness, surface treatment), pulp type, and mill equipment parameters. Therefore, precise formulation optimization and process adjustments must be implemented tailored to different paper types and production conditions.

Impact assessment on subsequent processes: Although preliminary studies indicate positive effects on finished paper quality, long-term large-scale application necessitates systematic evaluation of potential impacts on wet-end chemistry in paper machines, retention and filtration systems, and paper durability.

Comprehensive cost-benefit analysis: Although talcum powder itself is relatively expensive, the overall cost-effectiveness requires precise calculation when considering its energy-saving benefits.

Market awareness and acceptance: To position talcum powder's "energy-saving" function as a new selling point, extensive industry-wide promotion and demonstration of successful case studies are required to alter traditional perceptions.

VI. Conclusion and Prospects  

Centered on the research practices of Liaoning Xinda Talc Group Co., Ltd., this study systematically explores the "hidden" role of talc powder in reducing grinding energy consumption during papermaking pulping processes. The findings demonstrate that talc powder is more than just an inert filler in papermaking. Its unique flaky structure, low hardness, and surface properties enable effective reduction of friction loss and fiber damage through mechanisms such as lubrication and isolation, as well as stress dispersion and buffering, thereby significantly lowering pulping energy consumption. Experimental data from Xinda Talc Group confirm that under specific conditions, the addition of high-quality talc powder can reduce grinding energy consumption by 5%–12% while simultaneously improving paper quality.

This discovery has opened new avenues for energy conservation and resource efficiency in the papermaking industry, while redefining the application value of talc powder in this sector. Moving forward, Xinda Talc Group will deepen related research with three key priorities: 1) Establishing quantitative models linking talc powder properties, pulping processes, and energy-saving outcomes; 2) Developing customized talc powder products and supporting technologies tailored to different paper types and pulping equipment; 3) Conducting long-term industrial application tracking and comprehensive evaluations. The company also looks forward to collaborating with more paper manufacturers to promote widespread adoption of this green energy-saving technology across the industry, contributing to sustainable development in the papermaking sector.

References

[1] Chen Kefu. Complete Book of Pulp and Papermaking Engineering [M]. Beijing: China Light Industry Press, 2001.

[2] Liu Wenxia, Qiu Huayu. Principles of Wet Chemistry in Papermaking and Its Applications [M]. Beijing: China Light Industry Press, 2010.

[3] Zhang Meiyun, et al. Papermaking fillers and pigments [M]. Beijing: China Light Industry Press, 2015.

From theoretical analysis of energy-saving mechanisms in talc pulping slurries to dual experimental validations in laboratory and industrial settings, followed by evaluation of implementation prospects and challenges in the industry, this series of publications systematically decodes the "hidden" energy-saving effects of talc powder during papermaking pulping processes based on research practices by Xinda Talc Group. This study not only elevates talc powder from a conventional papermaking filler to an "energy-efficient functional material," but also provides innovative practical pathways for cost reduction, efficiency enhancement, and green sustainable development in the paper industry. We anticipate widespread adoption and deepened application of this technology across the sector.