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Bone char

Bone char, also known as bone black or bone charcoal, is a porous, carbon-rich material derived from the thermochemical conversion of animal bones, primarily consisting of calcium hydroxyapatite (70–76%), calcium carbonate (6–9%), and amorphous carbon (8–11%).^[1]^[2] It is produced by collecting, washing, and drying waste animal bones, followed by pyrolysis or carbonization in an oxygen-limited environment at temperatures ranging from 400°C to 1000°C for 2–4 hours, yielding 45–75% bone char with a surface area of 80–120 m²/g or higher when activated.^[1] This process removes organic matter, creating a mesoporous structure with functional groups that enhance its adsorptive properties.^[2] Bone char has been traditionally employed as a decolorizing filter in sugar refining, where it removes impurities and colorants from cane sugar liquors in fixed or moving bed systems.^[3]^[4] Beyond food processing, it serves as an adsorbent for environmental remediation, efficiently removing fluoride from drinking water (as approved by the World Health Organization), heavy metals like lead, cadmium, manganese, iron, nickel, and copper from wastewater (with removal rates of 75–98%), and organic pollutants such as dyes.^[2]^[1] In agriculture, bone char acts as a soil conditioner and phosphate fertilizer, providing 19.5–33.1 wt% P₂O₅ to immobilize contaminants like cadmium and lead while improving nutrient retention.^[1] Additionally, its catalytic properties support applications in biodiesel production (yields up to 97%), organic synthesis, and selective oxidation reactions.^[1] Emerging uses include energy storage in supercapacitors and batteries, leveraging its hierarchical porosity for high capacitance (up to 804 F/g).^[1]

History

Ancient and Pre-Industrial Uses

Bone char, also known as bone black, has one of its earliest documented applications in ancient Egypt around 2400 BC during the Old Kingdom's 5th Dynasty. Archaeological analysis of pigments from the mastaba tomb of Perneb at Saqqara reveals the use of black pigment derived from charred animal bones to paint interior walls and decorative elements, providing a deep, stable black tone for artistic representations. This material was ground into powder and mixed with binders to create paints that adhered well to limestone surfaces, highlighting bone char's role as an early synthetic pigment in funerary art.^[5]^[6] During the New Kingdom's 18th Dynasty (circa 1550–1292 BC), bone char saw expanded use in Thebes for artistic and decorative purposes. Artists in this period charred animal bones to produce pigments for temple murals, statues, and elite tomb decorations, often combining the black with gum arabic to form durable paints that symbolized fertility, the Nile's silt, and the afterlife. Evidence from pigment residues in Theban tombs confirms bone black's prevalence alongside other carbon-based blacks, underscoring its importance in the vibrant palette of royal and religious iconography.^[6]^[7] In pre-industrial Europe and Asia, bone char found practical applications beyond art, serving as a key base for black inks, mixed with binders to create deep-hue formulations for manuscripts and early printing, persisting through the medieval and Renaissance periods. Archaeological findings of bone char residues in ancient cooking and craft sites across these regions indicate byproduct utilization from animal processing, repurposed for pigment needs.^[8]^[9] These early uses laid the groundwork for bone char's later industrial-scale adoption in the 19th century.^[8]

Industrial Development

The industrial development of bone char began in the early 19th century with its commercialization for sugar refining. In 1815, Peter and John Martineau received a patent in the United Kingdom for utilizing bone char to decolorize sugar solutions, recommending 2 to 5 pounds of char per 100 pounds of sugar to achieve effective clarification.^[10] This innovation marked a pivotal advancement over earlier methods, enabling more efficient processing of raw sugar.^[11] Throughout the 19th century, bone char production expanded rapidly to support the decolorization of cane sugar imported through colonial trade networks, particularly from plantations in the Americas and Asia. Refineries in Europe and North America adopted it as a standard filtering agent, transforming the global sugar industry by improving the yield and purity of white sugar from these distant sources.^[12] This period aligned with the Industrial Revolution's demand for scalable refining techniques, positioning bone char as a key enabler of mass-produced sweeteners. In the 20th century, bone char underwent adaptations for broader industrial applications, including its use in cigarette filters derived from animal bone black as described in a 1967 patent.^[13] By the mid-20th century, global production hubs emerged in regions like Pakistan, India, and Argentina, where slaughterhouse bones were systematically collected and processed to supply refineries worldwide.^[14] These developments solidified bone char's role in international supply chains, building on its ancient precursors in pigment production for more refined, commercial-scale outputs.

Production

Raw Materials

Bone char is primarily produced from animal bones sourced as byproducts of the meat processing industry. These bones are typically obtained from cattle, pigs, sheep, and other mammals, providing a sustainable utilization of waste materials that would otherwise require disposal.^[15]^[16] Major suppliers include slaughterhouses in countries such as Argentina, India, Pakistan, and Afghanistan, where cattle bones form a significant portion of the raw material due to the scale of livestock farming and meat production in these regions.^[14] The bones are collected from these operations and transported to processing facilities, often in developing countries where raw material availability supports cost-effective production.^[17] Preferred bone types for bone char production are large, dense hard bones, such as bovine femurs, which yield higher quantities of the final product owing to their elevated mineral content and structural integrity during processing.^[1] While large mammal bones are preferred for traditional applications like sugar refining due to higher mineral content, softer bones from sources like poultry or fish can also be used in certain contexts, such as environmental remediation. To maintain quality and comply with food safety standards, only bones free from diseases, contaminants, or chemical residues—verified through inspections and testing—are selected, preventing risks in applications like sugar refining or water treatment.^[16] Pre-processing of the bones begins with thorough cleaning to remove adhering flesh, blood, and debris, followed by degreasing using volatile solvents or steam treatment to extract fats and gelatinous materials.^[18] Following degreasing, the bones are washed and dried. Sorting then eliminates non-bone organics, such as cartilage or marrow remnants, ensuring a uniform raw material suitable for subsequent pyrolysis. The global supply chain depends on consistent access to slaughterhouse waste, highlighting bone char's role in waste valorization amid growing meat consumption worldwide.^[19]

Manufacturing Process

The manufacturing process of bone char primarily involves the thermal decomposition of animal bones through pyrolysis in a low-oxygen environment to convert organic components into a carbon-rich char. Degreased bones, typically sourced from slaughterhouse by-products, are loaded into retorts or kilns and heated to temperatures between 450°C and 1000°C for 1 to 5 hours under an inert atmosphere such as nitrogen, producing char alongside byproduct gases and oils.^[1] This pyrolysis step yields approximately 45% to 75% char by weight, depending on the bone type and process conditions.^[16] Traditional bone char, particularly for sugar refining, is produced without activation to preserve its natural adsorption properties derived from the hydroxyapatite structure.^[20] However, optional activation may be applied post-pyrolysis through physical methods like steaming at temperatures above 700°C or chemical treatments with agents such as potassium hydroxide to increase porosity and surface area, though this is more common in modern applications for water treatment.^[1] After pyrolysis or activation, the resulting char is cooled, milled using equipment like ball mills, and sieved to achieve particle sizes of 0.5 to 2 mm, which are optimal for filtration uses in industrial settings. Quality control measures during this stage assess carbon content, typically 8-11%, and phosphate levels to ensure consistency for specific applications.^[16]^[1] The process is inherently energy-intensive due to the high temperatures required, with traditional batch kilns being gradually replaced by modern continuous furnaces for better efficiency and reduced variability. Emissions generated include carbon dioxide, sulfur dioxide, and particulates, which are quantified and mitigated through life cycle assessments in contemporary production facilities.

Properties

Chemical Composition

Bone char is primarily composed of 70–76% hydroxyapatite (\mathrm{Ca_{10}(PO_4)_6(OH)_2}), 9–11% amorphous carbon, and 7–9% calcium carbonate, along with trace elements such as magnesium.^[21] The exact proportions can vary based on production parameters, with higher pyrolysis temperatures generally reducing the carbon content while increasing the relative proportion of calcium phosphate minerals.^[16] This material typically exhibits a pH in the range of 8–11, owing to the buffering capacity provided by its phosphate components.^[22] In contrast to biochar or activated carbon, which are largely carbonaceous and rely on physical adsorption, bone char's inorganic phosphate matrix facilitates ion-exchange processes that enhance its selectivity for certain contaminants.^[16] The hydroxyapatite structure in bone char is confirmed through X-ray diffraction (XRD) analysis, which identifies characteristic crystalline phases, while Brunauer–Emmett–Teller (BET) analysis measures the specific surface area, typically ranging from 50 to 100 m²/g for standard preparations.^[16]

Physical and Adsorption Characteristics

Bone char exhibits a porous granular structure, characterized by a predominantly mesoporous architecture with pore diameters ranging from 2 to 50 nm, which contributes significantly to its high surface area and adsorption efficiency.^[23] The material appears black due to its carbon content and has a bulk density typically between 0.4 and 0.8 g/cm³, making it lightweight yet durable for filtration applications.^[24] This porosity arises from the thermal decomposition of organic components in animal bones during production, resulting in a network of interconnected pores that facilitate the diffusion and trapping of contaminants.^[25] The adsorption properties of bone char stem from its hydroxyapatite content, enabling high affinity for anions such as fluoride through ligand exchange mechanisms involving phosphate groups, with reported capacities of 5-11 mg/g under optimal conditions like pH 3-7.^[26] It also effectively binds heavy metals, including lead and arsenic, via surface complexation and electrostatic attraction, achieving capacities up to 50-78 mg/g for ions like Pb²⁺ and Zn²⁺ depending on pH and modification.^[27] Additional mechanisms include precipitation, where metal ions form insoluble compounds with calcium and phosphate on the surface.^[28] Adsorption behavior is often modeled using the Langmuir isotherm, which assumes monolayer coverage on homogeneous sites:

q_e = \frac{q_{\max} K_L C_e}{1 + K_L C_e}

where q_e is the equilibrium adsorption capacity (mg/g), q_{\max} is the maximum adsorption capacity (mg/g), K_L is the Langmuir constant (L/mg), and C_e is the equilibrium concentration (mg/L). This model fits experimental data well for fluoride removal, highlighting the finite binding sites on bone char.^[29] Bone char demonstrates good durability and regenerability, particularly when treated with NaOH solutions to desorb contaminants, retaining 70-80% of its initial adsorption capacity after multiple cycles.^[30] This process involves ion exchange to release bound fluoride or metals, allowing reuse in batch or column systems without significant structural degradation. The phosphate-based composition briefly supports this binding, enhancing long-term performance in repeated applications.^[31]

Uses

Sugar Refining

Bone char is extensively used in the refining of cane sugar to decolorize and purify the liquor during the affination process. Raw sugar is first melted into a syrup, which is then percolated downward through large fixed-bed columns or cisterns filled with bone char granules, typically around 36 metric tons per column. The porous structure of the bone char adsorbs colorants such as melanoidins, phenolic compounds, amino acids, and other impurities, along with inorganic ions like ash and divalent cations, yielding a clear, colorless fine liquor for subsequent crystallization into white sugar.^[20]^[32] This adsorption process achieves high efficiency, removing 90-99% of color from the sugar liquor, with the highest removal rates occurring early in each operational cycle. A single filter column requires approximately 70,000 pounds (31,751 kg) of bone char, derived from the bones of about 7,800 cows, highlighting the scale of material needed in industrial operations. In the United States, bone char remains the preferred decolorizing agent for most cane sugar refineries, including major producers like Imperial Sugar and American Sugar Refining, accounting for the majority of refined cane sugar on store shelves as of the early 2000s; it is not used for beet sugar refining. Globally, bone char continues to be a standard in cane sugar processing, particularly for non-organic and non-vegan-certified products, though exact usage percentages vary by region and have shifted toward alternatives in some markets.^[20]^[32] After use, spent bone char is regenerated through backwashing with hot water to displace and remove residual sugar syrup, followed by thermal treatment in kilns at approximately 550°C (1,022°F) to oxidize and eliminate adsorbed organic matter, restoring its adsorptive capacity. This regeneration allows the char to be reused multiple times per operational cycle, with columns typically running for about 60 hours before regeneration; the material can last 5-10 years in service before requiring full rejuvenation or replacement due to gradual degradation. In 1974, bone char was employed in 42% of U.S. refineries but handled 69% of the nation's sugar refining capacity, underscoring its prevalence in larger facilities.^[20]^[32]

Water Treatment

Bone char is widely applied in water treatment for the removal of fluoride from groundwater in regions affected by endemic fluorosis, such as East Africa (e.g., Tanzania and Kenya) and India, where elevated fluoride levels exceed the World Health Organization (WHO) guideline of 1.5 mg/L.^[33] The adsorption capacity of bone char for fluoride typically ranges from 1 to 20 mg/g, with optimal performance observed at pH levels between 5 and 7, where the hydroxyapatite component facilitates ion exchange and surface complexation.^[33]^[34] In addition to fluoride, bone char effectively removes heavy metals such as arsenic (As), lead (Pb), and cadmium (Cd) through mechanisms involving phosphate precipitation and cation exchange with calcium sites on the hydroxyapatite structure.^[35] Bone char adsorbs phosphates from wastewater, leveraging its high calcium content.^[36] Bone char is integrated into point-of-use systems, including household ceramic pot filters infused with the material for decentralized treatment, and larger community-scale fixed-bed columns capable of processing 10 to 2,000,000 L per day.^[37]^[33] These systems align with the WHO guideline of 1.5 mg/L for fluoride in drinking water, supporting provision in resource-limited settings.^[33] Performance evaluations demonstrate that bone char can reduce fluoride concentrations from 10 mg/L to below 1.5 mg/L, often requiring approximately 496 kg per 100 m³ of water treated, depending on flow rates and initial contaminant levels.^[33] Breakthrough curves for column-based systems are commonly modeled using the Thomas equation to predict adsorption bed exhaustion and optimize design parameters for sustained operation.^[38]

Pigment Production

Bone char, when used as a pigment, is processed by finely milling the charred material to a particle size of approximately 1 μm, resulting in bone black or ivory black with a carbon content of 10-20% that imparts opacity and depth to the color.^[39]^[40]^[41] This fine grinding enhances the pigment's dispersibility in media, distinguishing it from coarser forms used in other applications.^[42] In artistic and industrial contexts, bone black serves as a versatile colorant in oil paints, where it provides a warm, opaque black suitable for underpainting and glazing; in inks for printmaking and calligraphy, offering reliable flow and adhesion; and in ceramics, where it contributes stable black tones to glazes and underglazes.^[43]^[44]^[45] Its lightfastness and non-toxicity make it a preferred natural alternative to synthetic carbon blacks, particularly in fine arts where permanence is essential.^[46]^[47] Historically, bone black was the dominant black pigment from prehistoric times through the 19th century, valued for its warm undertone in oil paintings and murals, until synthetic iron oxide blacks like Mars black emerged in the mid-20th century as cheaper, more consistent alternatives.^[44]^[48] Despite this shift, it remains favored in fine arts for its subtle brownish-black hue and traditional appeal.^[49] Ancient applications, such as in Egyptian tomb paintings around 2650 BC, served as early precursors to these refined uses.^[6] Key properties for pigment applications include high tinting strength, allowing effective color dilution up to a 1:100 masstone-to-tint ratio, and chemical stability in alkaline environments owing to its phosphate matrix of calcium hydroxyapatite.^[50] These attributes ensure durability in mixed media without fading or reactivity issues.

Agricultural and Remediation Applications

Bone char serves as an effective soil amendment by providing a source of phosphorus, typically containing 20–30% P₂O₅, which acts as a fertilizer to address nutrient deficiencies in agricultural soils.^[1] This phosphorus content enhances soil fertility, particularly in phosphorus-limited environments, while the calcium hydroxyapatite structure contributes to long-term nutrient supply. In sandy soils, bone char improves nutrient retention by 30-45%, reducing leaching losses and promoting sustained availability of essential elements like nitrogen and potassium.^[51] In environmental remediation, bone char adsorbs heavy metals from contaminated sites, facilitating immobilization of pollutants such as cadmium (Cd) through mechanisms including ion exchange and surface complexation, with adsorption capacities reaching up to 228 mg/g for Cd²⁺.^[52] It is often incorporated into biochar blends to support sustainable agriculture, combining the high phosphorus content of bone char with the organic carbon stabilization properties of plant-derived biochars to improve soil structure and reduce metal bioavailability.^[53] Recent studies from the 2020s demonstrate that bone char application increases crop yields by 20-36% in phosphorus-deficient soils, as observed in trials with maize and soybeans where it enhanced plant-available phosphorus sevenfold compared to unamended controls.^[51] Additionally, bone char has shown promise in electrochemistry and catalysis applications for pollutant degradation, such as mediating the dechlorination of trichloroethylene or enhancing persulfate-based oxidation of pharmaceuticals like acetaminophen.^[16] Typical dosages for soil application range from 1-5% by soil weight, equivalent to 4-10 t/ha depending on soil depth, allowing for gradual nutrient release without overwhelming the system.^[54] The slow-release phosphate mechanism involves the acid-driven dissolution of hydroxyapatite in bone char, following the reaction:

\text{Ca}_5(\text{PO}_4)_3\text{OH} + 8\text{H}^+ \rightarrow 5\text{Ca}^{2+} + 3\text{H}_2\text{PO}_4^- + \text{H}_2\text{O}

This process ensures controlled phosphate availability, minimizing runoff and supporting prolonged crop nutrition.^[55]

Societal and Environmental Aspects

Ethical and Sustainability Concerns

Bone char, produced from charred animal bones—predominantly cattle—raises significant ethical concerns due to its animal-derived nature, rendering products like refined white sugar non-vegan despite the absence of direct animal residues in the final product.^[56] Organizations such as People for the Ethical Treatment of Animals (PETA) have campaigned against its use in sugar refining since the early 2000s, highlighting the inhumane slaughter involved in sourcing the bones and urging consumers to boycott cane sugars processed with it in favor of vegan alternatives like beet sugar.^[56] These efforts have led to widespread awareness and selective avoidance among vegans, with PETA recommending unrefined options such as Sucanat or turbinado sugar to eliminate any involvement of animal byproducts.^[57] The sourcing of bones from slaughterhouse waste indirectly supports factory farming practices, where cattle endure cramped, unsanitary conditions prioritizing profit over welfare, exacerbating ethical dilemmas for consumers opposed to animal exploitation.^[58] In regions with cultural reverence for cattle, such as India under Hinduism, the use of cow bones in bone char evokes sensitivities, as foreign refined sugars are often deemed non-vegetarian, prompting calls for purely plant-based clarification methods in local production.^[59] This has fueled broader societal discussions on hidden animal ingredients, with media references in vegan advocacy videos and online resources debunking myths, such as unfounded claims of human bones from World War II being incorporated into bone char, which lack historical evidence and stem from wartime misconceptions about resource use.^[60] Regulatory frameworks in the European Union and United States address these issues through voluntary vegan labeling standards, which prohibit animal-derived processing aids like bone char to ensure product integrity for ethical consumers.^[61] Certifications such as the Vegan Trademark explicitly verify avoidance of bone char, while growing consumer tools, including apps like "Is It Vegan?", enable barcode scanning to identify sugar sources and flag non-vegan items, enhancing awareness and choice.^[62]

Alternatives and Future Prospects

Activated carbon serves as a primary alternative to bone char for general adsorption applications, such as water purification and sugar refining, though it typically incurs higher production costs due to energy-intensive activation processes from sources like coconut shells or wood.^[63] Biochar derived from plant waste, including agricultural residues like woodchips or coconut shells, offers an eco-friendly substitute particularly for soil amendment and remediation uses, avoiding animal-derived materials while providing similar carbon sequestration benefits.^[63] Synthetic hydroxyapatite, produced through chemical precipitation methods, is another viable option for targeted fluoride removal from drinking water, leveraging its phosphate structure for ion exchange without relying on biological feedstocks.^[64] In terms of comparative efficacy, plant-based biochars exhibit 20-50% lower fluoride adsorption capacity than bone char—for instance, coconut shell-derived activated carbon achieves up to 4.55 mg/g and 90% removal efficiency under optimal conditions, compared to bone char's 9.09 mg/g and 96% efficiency—yet they eliminate animal input concerns and maintain broad applicability in low-concentration scenarios.^[65] For sugar decolorization, wood-based activated carbons from agricultural by-products like sugarcane bagasse demonstrate superior performance to bone char in color removal, though less effective in ash reduction while operating in granular systems with comparable retention times.^[66] Future prospects for bone char include the development of hybrid composites, such as ZnO/bone-char materials, which enhance catalytic and adsorptive properties for pollutant removal by combining bone char's mineral structure with metal oxides for improved stability and selectivity.^[67] Ongoing research emphasizes recycling waste bones through pyrolysis to create adsorbents in a circular economy framework; for example, 2024 studies on slow pyrolysis of cow bones have produced bone char with high surface area (up to 77 m²/g) and effective copper removal capacities exceeding 20 mg/g from acidic solutions.^[68] Life cycle assessments reveal that bone char production generates 2-5 kg CO₂-equivalent emissions per kg, primarily from high-temperature carbonization processes,^[17] whereas biochar from plant sources emits 1-2 kg CO₂-eq/kg but offers potential for net carbon-negative applications in agriculture through soil carbon stabilization.^[69] These comparisons underscore opportunities for hybrid systems to reduce environmental footprints while preserving efficacy.

References

[1]
Value-added materials recovered from waste bone biomass - NIH
Waste bone derived hydroxyapatite and bone char have found applications as a catalyst or catalyst support in organic synthesis, selective oxidation, biodiesel ...2.1. Bone Char · 2.2. Hydroxyapatite (ha) · 3.4. Bone Tissue Engineering
[2]
A comprehensive review of bone char: Fabrication procedures ...
Dec 1, 2024 · This review aims to provide information about the thermochemical conversion method of recycling waste bone to fabricate bone char
[3]
[PDF] AP-42, Section 9.10.1.1: Sugarcane Processing - EPA
Bone char or activated carbon are used in either fixed or moving bed systems. Spent adsorbent is removed from the bed, regenerated, and stored for reuse. The ...
[4]
Removal of Mn, Fe, Ni and Cu Ions from Wastewater Using Cow ...
Bone charcoal has traditionally been used in the sugar refining industry to remove color from sugar solutions. Recent studies have used bone charcoal to ...
[5]
The Pigments of the Tomb of Perneb. - ACS Publications
This article is cited by 1 publications. J. RIEDERER. RECENTLY IDENTIFIED EGYPTIAN PIGMENTS. Archaeometry 1974, 16 (1) , 102- ...
[6]
Product History - Ebonex Corporation
During the 18th Dynasty in Thebes, artists ground bone char with gum to create early forms of paint. Over time, this pigment found various applications beyond ...
[7]
Discovering manganese-based blacks in the grave goods of Kha ...
In Ancient Egypt, the predominant black pigments were carbon-based, produced through charring plant materials (charcoal), soot (lampblack) [4], or animal ...<|control11|><|separator|>
[8]
Pigments through the Ages - History - Bone black - Webexhibits
Bone black has been identified in prehistoric paintings and found in Egyptian, Greek and Roman art. It is found throughout European medieval and Renaissance ...Missing: ancient | Show results with:ancient
[9]
Ochre to Bone Black: The First Pigments | Pigments in Focus Series
Evident in prehistoric, Egyptian, Greek, and Roman art, bone black continued to be a prominent pigment during the Middle Ages and Renaissance. Dutch painters ...
[10]
Bone Char made in Central Park, New York - the Biochar Journal
Nov 1, 2015 · The original bone char patent in 1815 by Peter and John Martineau called for the use of 2 to 5 pounds of char per 100 pounds of sugar (6).
[11]
the activated carbons and their use in removing objectionable tastes ...
sugar solutions. Peter and John Martineau patented in England the use of bone char in 1815, and this kept the use of vegetable chars in the background for ...
[12]
Bone Char discussion - Sugar Knowledge International Ltd
A material called 'bone char' was used extensively to remove colour from raw cane sugar in the refining process. Modern technology has largely replaced bone ...
[13]
US3319629A - Filter cigarette - Google Patents
... bone black, or carbon black (lamp black, Paris black) made by partial cornbustion of natural gas. The activated carbon present in filters of the present ...
[14]
Vegetarian Journal Mar/Apr 97 Sugar and Other Sweeteners
Bone char cannot be produced or bought in the United States (3). Bone char is derived from the bones of cattle from Afghanistan, Argentina, India and Pakistan.
[15]
Bone Char - an overview | ScienceDirect Topics
Bone char consists of ground animal bones that have been charred to remove all OM. Bone char mainly consists of calcium carbonate, calcium phosphate, and AC.
[16]
Preparation, characterisation and applications of bone char, a food ...
Aug 1, 2023 · Here bone chars' applications in environmental remediation, sustainable agriculture, catalysis and electrochemistry are discussed; several ...
[17]
Assessing the environmental impact of bone char production by in ...
Sep 20, 2022 · It is particularly popular in developing countries owing to the readily available raw materials, simple manufacturing process, low cost, and ...
[18]
[PDF] TEXTILE AND OTHER FACTORY WASTES
bones may be ground without preliminary treatment, or they may be treated with a volatile solvent or boiled with steam to remove fats and gelatin and then ...
[19]
Bone char for water treatment and environmental applications
Bone char is a promising and effective material for environmental applications. Bone char is efficient in removing pollutants (eg, metals, fluoride) from water.
[20]
[PDF] CANE SUGAR REFINING - Environmental Protection Agency
The waste water produced by a crystalline sugar refinery using bone char for decolorization. The majority of waste stream components are char wash water which.
[21]
A comprehensive review of bone char: Fabrication procedures ...
Dec 1, 2024 · Owing to its unique pore structure and chemical/mineral compositions, bone char can be widely used as an adsorbent, soil conditioner, catalytic ...
[22]
Effect of pyrolysis conditions on bone char characterization and its ...
Bone char was developed from sheep bones at different temperatures. •. Surface chemistry were characterized via quantitative and qualitative analysis ...<|separator|>
[23]
Waste bone char-derived adsorbents: characteristics, adsorption ...
Waste bones can be converted into bone char (BC), which can be used as an adsorbent for removing pollutants from wastewater and effluent gas.
[24]
https://www.anthracitefilter.com/products.php?page=Bone%20Char
[25]
Bone-char from various food-waste: Synthesis, characterization, and ...
In addition, pores size distribution results in Fig. 5b illustrate that the curves are primarily focused in the range of pore size between 1.5 and 2.5 nm, ...
[26]
Study the Use of Activated Carbon and Bone Char on the ... - NIH
For example, Bone char from cattle can adsorb ~11 mg/g of fluoride at pH 3 when 20 mg/L of fluoride impurities are present.<|control11|><|separator|>
[27]
Tailoring the adsorption behavior of bone char for heavy metal ...
Jul 14, 2016 · Concerning the adsorption capacity, the metal uptake of tested samples ranged from 50.2 to 66.7 mg/g for Zn2+, 54.5 to 78.5 mg/g for Ni2+ and ...
[28]
Bone char as a cost-effective material for stabilizing multiple heavy ...
Sep 20, 2022 · Bone char (BC) is a granular substance mainly composed of hydroxyapatite, which is produced by the pyrolysis of animal bones and is a special ...
[29]
Evaluation of Fluoride Adsorption Mechanism and Capacity of ...
Jun 26, 2021 · The fluoride adsorption capacity of three types of bone char (BC), including cow BC (CBC), chicken BC (CKBC), and pig BC (PBC), was examined.
[30]
[PDF] CHEMICAL REGENERATION OF BONE CHAR ASSOCIATED WITH ...
Chemical regeneration of bone-char was feasible, and a reduction in adsorption capacity of 30% was observed only after five adsorption/desorption cycles.Missing: retention | Show results with:retention
[31]
Adsorption of fluoride, arsenate and phosphate in aqueous solution ...
▻ The adsorption mechanism might be both electrostatic attraction and ligand exchange. Introduction. Fluoride, arsenate and phosphate exert a significant ...
[32]
Is Your Sugar Vegan? | Vegetarian Journal
The VRG revisits the issue of bone char use in the sugar industry, examines emerging practices for refining sugar, and discusses alternatives to sugar refined ...Missing: 19th century
[33]
Bone char as a green sorbent for removing health threatening ...
Bone char production and characteristics. Globally, millions of tons of bone waste are produced annually due to the meat industry. According to the Organisation ...Missing: quantity | Show results with:quantity
[34]
Adsorption of Fluoride from Water Solution on Bone Char
A comparison of fluoride adsorption capacities among several adsorbents revealed that the adsorption capacity of the bone char was 2.8 and 36 times greater ...
[35]
Application of bone chars for the removal of chemical contaminants ...
Sep 21, 2025 · This present study reports the comprehensive review on the application of bone chars for the removal of heavy metals, fluorides, ...
[36]
Bone char for water treatment and environmental applications
Bone char (BC) appears as one of the promising solutions for the removal of several pollutants for the management of water treatment. BC is a porous, black, and ...
[37]
Development of Ceramic Filters for Household Water Treatment in ...
2) Increasing quantity of Bone char in the ceramic filter composition increased the filter's ability to reduce fluoride con- centration in the treated water ...
[38]
Modeling of fixed-bed adsorption of fluoride on bone char using a ...
Jul 15, 2013 · This study introduces a hybrid model based on the Thomas equation and artificial neural networks (ANNs) for the modeling of unsymmetrical breakthrough curves
[39]
https://www.naturalpigments.com/bone-black-1kg.html
[40]
Color Pigments - Carbon Black - GRAPEWOOD COLORS
Bone/ivory black is obtained through the incomplete burning of bone/ivory (10-20% carbon). There are various names for the varying qualities of bone black; ...
[41]
Jackson's Artist Pigments: Colour Information and History
Jun 1, 2023 · Do not spray-apply. Particle Size: Approx 1 µm. History / How It ... Pigment: Ivory Black. Index No: PBk9. Colour Description: Warm black.
[42]
https://www.naturalpigments.ca/bone-black-pigment.html
[43]
https://www.naturalpigments.com/bone-black-oil-paint.html
[44]
Pigments through the Ages - Overview - Bone black - Webexhibits
It is made from charring of bones or waste ivory. It was used from prehistory and it is in use until today. Ivory Black is therefore the least pure form of ...
[45]
Making Bone Black Oil Paint - Damian Osborne
Aug 18, 2021 · The pigment is also extremely oil absorbent. I found that I needed a ratio of one part pigment to 1.86 parts cold-pressed hand-refined linseed ...Missing: masstone | Show results with:masstone<|control11|><|separator|>
[46]
the material attributes of paints - Handprint.com
In many pigments, smaller particle size also reduces the pigment permanence ... carbon [bone] black. 2.4 . 2.5, aluminum hydrate (laking substrate)
[47]
Bone black - MFA Cameo
Mar 13, 2025 · An impure black carbon pigment prepared from charring animal bones. Bone black is composed of about 10% Carbon and 84% Calcium hydroxyapatite.
[48]
Chrysler Museum of Art |
Jul 23, 2020 · Mars black— a synthetic, high-opaque, fast-drying, black pigment—was introduced in the middle of the twentieth century.Missing: alternatives | Show results with:alternatives
[49]
Colour Stories Black | Podcast | National Gallery, London
Oct 17, 2025 · ... pigments, all of which are synthetic iron oxides. This was invented in the 20th century as an alternative to the natural black pigments.
[50]
https://www.naturalpigments.com/bone-black-50ml.html
[51]
[PDF] CARBON BLACK 1. Exposure Data - IARC Publications
Bone black is used primarily as a colourant in artists' paint and for tinting vinyl fabrics for upholstery and automotive interiors. The carbon content of bone ...<|control11|><|separator|>
[52]
Carbon Black - Printing Processes and Printing Inks ... - NCBI - NIH
Bone char is made by carbonizing bones and is used principally in sugar refining. Bone black is a pigment derived from bone char, used primarily as a colourant ...
[53]
[PDF] Bone char: characterization and agronomic application as an ...
This study aimed to characterize bone char and conduct a comparative analysis with both soluble (triple superphosphate) and non-soluble. (Bayóvar phosphate rock) ...
[54]
Bone char outperforms biochar in phosphorus-deficient soils
Bone char outperforms biochar in phosphorus-deficient soils: Comparative analysis of soil fertility enhancement and greenhouse gas mitigation.
[55]
Sorption of Cd2+ on Bone Chars with or without Hydrogen Peroxide ...
Mar 22, 2022 · The main mechanisms of Cd2+ adsorption included the ion exchange of lattice Cd2+ from the bone char with cadmium ions from the aqueous solution, ...
[56]
Using Bone Char as a Renewable Resource of Phosphate ...
Oct 2, 2024 · The use of bone char as a phosphate fertilizer is a promising strategy in sustainable agriculture because it is a renewable source of phosphorus ...
[57]
A review on biochar's effect on soil properties and crop growth
The effect of biochar on soil properties, heavy metal remediation or crop yield depends on biochar type, its dose, soil type, agroclimatic condition, crop ...<|separator|>
[58]
Bone char: characterization and agronomic application as ... - SciELO
Release profile of P from bone char strongly suggests this material can be used as a slow-release P source, with intermediate solubility between soluble and non ...
[59]
Is Sugar Vegan? - PETA
Jul 8, 2016 · Typically, sugar is made from sugarcane, sugar beets, or coconuts. Beet and coconut sugar are never processed with bone char. What about brown ...Missing: percentage | Show results with:percentage
[60]
Are animal ingredients included in white sugar? - PETA
Bone char—often referred to as natural carbon—is widely used by the sugar industry as a decolorizing filter, which allows the sugar cane to achieve its ...
[61]
Uncovering the (Less Than) Sweet Truth: The Hidden Dangers of Bone Cha
### Summary of Ethical Concerns, Animal Welfare, and Sourcing of Bone Char
[62]
Beauty Without Cruelty - India
Jul 14, 2025 · The refined sugar (brown, white and powdered) manufactured abroad usually involves the bone char filter process. (Bones from cows are the only ...
[63]
Did the Nazis Really Use Bodies of Murdered Jews to Make Soap?
Feb 11, 2020 · The Germans used the corpses of murdered Jews to mass-produce bars of soap, and that these sacred remnants should be included in their exhibits.<|separator|>
[64]
Vegan Label Laws | White Paper Importance of Vegan Certification
An ethical Vegan should only want a Vegan certification. For example, a product made with sugar that uses bone char to refine the sugar can be plant-based.
[65]
Is It Vegan? App Review - VegDispatch - WordPress.com
Oct 13, 2016 · The Is It Vegan? app is available in the app store for free. It is a great quick resource to see if processed foods are vegan. I have been using ...
[66]
Biochar versus bone char for a sustainable inorganic arsenic ...
Bone char effectively removed As(V) from drinking water (up to 95.2%) at pH 10 and an initial As(V) concentration of 0.5 mg/L (Chen and Chai, 2008). The effect ...
[67]
Enhanced fluoride removal from drinking water using non-calcined ...
This study presents the advantage of synthetic un-calcined hydroxyapatite over calcined hydroxyapatite for fluoride removal.
[68]
Defluoridation efficiency of animal bone char and coconut shell ...
Feb 19, 2025 · ... adsorption capacities ranging from 1.1 to 2.2 mg/g depending on pH and initial fluoride concentration (Alhassan et al. 2021). Other bio ...
[69]
[PDF] Granular Activated Carbons From Agricultural By-Products
Jan 1, 2000 · Four systems of decolorization are used in the sugar refining process: bone char, granular activated carbons, ion exchange resins, and ...<|control11|><|separator|>
[70]
ZnO/bone-char hybrid composite: Catalyst preparation ...
Aug 7, 2025 · This study was aimed at the development of the ZnO/bone-char (ZnO/BC) hybrid composite and it was characterized for its suitability for the ...
[71]
Slow Pyrolysis of Waste Cow Bone for Biochar Production and Its ...
Dec 17, 2024 · This study presents a comprehensive analysis of bone char derived from cow bones, focusing on its characterization and potential ...Missing: manufacturing | Show results with:manufacturing