Mineralogical and physicochemical characterization of Ngaye alluvial clays (Northern Cameroon) and assessment of its suitability in ceramic production

Soureiyatou Fadil-Djenaboua, Paul-Désiré Ndjigui a, Jean Aimé Mbey b,c,∗
a Department of Earth Sciences, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon b Department of Inorganic Chemistry, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon c Laboratoire Interdisciplinaire des Environnements Continentaux, Université de Lorraine, UMR 7360, 15 Avenue du Charmois, B.P. 40, F-54501
Vandoeuvre-lès-Nancy Cedex, France

Original Article: https://ac.els-cdn.com/S2187076414000992/1-s2.0-S2187076414000992-main.pdf?_tid=e47ac0d8-3008-4c40-b009-c3dc6bec9a85&acdnat=1523718815_3099bd4bb01beeeaeec02b561e4d4d82


Mineralogical and chemical characterization of DD3 kaolin from the east of Algeria

Hamza Senoussi a, Hocine Osmani a, Christian Courtois b, Mohamed el Hadi Bourahli a,∗ a Non Metallic Materials Laboratory, Institute of Optics and Precision Mechanics, University Ferhat Abbes, Setif 1 Algeria
b Ceramics Materials and Processes Laboratory, University of Valenciennes and Hainaut-Cambresis, France.

The mineralogical and chemical characteristics, based on X-ray diffraction (XRD) and scanning electron microscopy, of a kaolin known as DD3, from eastern Algeria were examined in the present study.

The results showed that kaolin DD3 has an alumina content of 39%. The SiO2/Al2O3 molar ratio of 2.14 is close to that of a pure halloysite. The hematite concentration is relatively large and the flux oxides ratios remain as acceptable impurities. Microscopic observations showed a predominant tubular halloysite phase, flattened hexagonal platelets corresponding
to the presence of kaolinite and its polymorphs (nacrite, dickite), and hydrated alumina.

The SiO2/Al2O3 molar ratio and tubular DD3 suggest possible uses in technical ceramics and nanotechnology applications.
Analysis by XRD revealed the presence of many phases. Thermal treatment at 450 ◦C and chemical treatment with HCl confirmed the presence of halloysite. The inclusion in the clay of organic molecules (dimethylsulfoxide (DMSO), DMF, and diluted glycerol) showed that the DMSO led to expansion of the inter-planar distance. The intercalation by DMSO molecules resulted in a shift of the basal peak from 10 to 11.02 A˚ and partial displacement of the peak from 3.35 to 3.65 A. ˚ These two peaks are characteristic of halloysite. The presence of residual nacrite was also confirmed by the shift of the peak observed at 3.35 A. ˚
A full analysis of the XRD patterns using the Match software, based on these results, showed that the DD3 clay consists of >60% halloysite.

Original Article at: https://ac.els-cdn.com/S0366317515001260/1-s2.0-S0366317515001260-main.pdf?_tid=26e52889-5066-480f-b857-c000bb1d6d3c&acdnat=1523718766_594018c22dd1ec83f91c55473e1eab0b

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Pot Filter Arsenic Removal with Bone Char Attachment

Link to original article: https://ojs.library.queensu.ca/index.php/ijsle/article/view/5261/5150

A Sustainable and Simple Solution in Resource-poor Settings

Stephen D. Passman – Saint Louis University
Tyler J. White, MPH – Saint Louis University
Roger D. Lewis, PHD, CIH – Saint Louis University

The results suggest that the designed test filter has a significant potential for removing arsenic concentrations to below both WHO and EPA drinking water standards. In addition, the clay pot filter alone demonstrated substantial reduction in the concentration of arsenic. Further research must be done to investigate longevity and practicality of the test filter, and to explore the extent to which reduction in arsenic concentration is attributable to the additional bone char layer versus the clay pot filter.
Our research team aims to continue investigating the new design to maximize removal of arsenic, other harmful metals, and bacteria. Further development will also include finding the optimal pore size and surface area for maximum arsenic adsorption to the bone char layer and the clay pot itself. Given the variance in manufacture methods of different communities producing the clay pot filters, identifying physical characteristics that result in optimal arsenic adsorption can help promote best practices for improving the effectiveness of the filters. Finally, connecting with NGOs working in resource-poor communities is critical to improving POU clay pot water filters for enhanced filtration and better health outcomes.

Point-of-Use Water Filtration for Arsenic:

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Fall 2014 News

UNC Chapell Hill, October 2014
Ceramic technician Burt Cohen will be presenting at the University of Chapel Hill conference on Water and Health.

The Ceramic Pot Filter side session is scheduled for Friday, Oct 17, 8:30am – 12:00pm. The purpose of the side session is to bring together those involved in ceramic pot filter manufacturing, marketing, dissemination and research in order to share successes and challenges over the past year and discuss future directions.

Filter Setter
We are currently forming a second prototype filter setter. The filter setter is used for stacking the filters together inside the kiln in a dense configuration. The setter not only nests the filters closely together, but should distribute the weight of the filters onto the support, rather than onto each other. A denser kiln stacking will allow more efficient use of space, reduce fuel costs, and improve the productivity of existing kilns. We hope that this setter will be able to be formed on the filter press.

Prototype mold Set
UK donor, Howells Llc. has produced an ovoid mold set of cast aluminum. This prototype set has a flat bottom but rounded sides, and incorporates several other small changes to the filter form. We hope that this prototype will improve strength and flow rate capabilities of the filter without requiring special drying and handling practices. Several rounds of experiments will be preformed before the mold set reaches the field-testing stage.

Prototype Press
Howells Llc. has also manufactured a prototype press which incorporates some potential advancements. Specifically, the press uses a flipping action for ejection, and is designed to be adaptable to manual, electric, or pneumatic hydraulic pistons for automation. It is hoped that this ejection method will lead to a method of ejection which will not require plastic bags, however, none of the experimental mold-release agents have yielded successful results so far.

Guinea Bissau
Although parts of West Africa have been heavily affected by the Ebola virus, our partners in Bissau are now in advanced stages of building the factory enclosure. We hope to begin batch tests and establish production in 2015. This project continues to benefit from area specific fund raising efforts including generous donations by the Canadian charity “Active Compassion” which helped pay for the first pound of colloidal silver. That’s enough silver for over 3300 filters.


The following questions highlight steps you can take to ensure your project’s success:

A. Understanding the local situation is key to a successful project.

  • What water sources do most locals use?
  • What are the impurities that must be removed?
  • Do people currently filter, boil, chlorinate, or otherwise purify their water?
  • What other purification methods are locally available? At what price?
  • What studies have been done to learn if people in the local community are receptive to the idea of using this or any kind of water filter?

  • Have they traditionally used ceramic water jugs for storage in the past?
  • What is the climate? Is there a rainy season?
  • How long?
  • Is the area politically stable?
  • Identify local laboratories capable of conducting water quality tests.

B. We recommend partnering with an existing pottery or brick-making workshop, ideally one that would have experience with marketing and health. Utilizing competent local potters will help ensure project success.

  • Is there presently a relationship between the potters or pottery collective and the sponsoring organization?
  • What kind of pottery do they produce?
  • What temperature do they fire to?
  • Do they have a history of being able to meet quotas?
  • Do local potters also have the experience and ability to fabricate lidded clay receptacles with a five to seven gallon capacity?
  • How far are the potters’ sites from the sponsoring organization’s operations?
  • How will management of the facility be structured? It will be very important to have a highly involved liaison responsible for management and communications between the two groups.
  • How will employees/skilled labor be paid?
  • By whom?
  • What is the distance between the factory site and the market (projected distribution area)?

C. Having a sustainable marketing plan is even more critical than the initial level of funding.

  • Who will provide the financial resources ($25,000-$30,000 USD) for start up?
  • How many visits by PWB consultants including airfare, per diem and stipend have been budgeted?
  • Who will provide the on-going business loans or subsidies for marketing?
  • For inventories of plastic components?
  • How large is their in-country staff?
  • What is the procedure for attaining approval and/or quality recognition from the Ministry of Health?

Identify local health promoters/NGOs through which the filter can be marketed in bulk. Contact them to evaluate their interest in the product.
Identify a local print shop to make brochures; instructional stickers; and educational, health, and marketing materials.

D. Communications

  • Does the ceramic workshop communicate through the internet?
  • Does the site have Internet access within or nearby?
  • Do they have a website?
  • Does anyone there speak, read and write English or Spanish?

E. The availability of facilities and suppliers can also determine project sustainability.

  • How far from the workshop is an adequate and affordable clay supply?
  • Is the clay plastic and of good quality?
  • How do the potters presently process their clay?
  • How far away is the site located from an adequate and affordable source of fuel and combustible (burnout) materials?
  • How will the clay, fuel, and combustible materials be transported, by whom, and at what cost?
  • Does the site have electricity? For how many hours a day?
  • What voltage and amperage is consistently available?
  • Does the site have piped water or a consistent water supply? How often is water unavailable?
  • Are high quality bricks available for kiln building? What sizes are available?
  • Is there a machine shop where repair items can be fabricated nearby?
  • Are there any restrictions on the importation of colloidal silver?
  • Is there a nearby source of affordable plastic bags?

Identify your local or foreign supplier of plastic five gallon pails and oversized lids; price, and availability.
Identify your local or foreign supplier of plastic faucets; price, and availability.

Needed Equipment
Please study the list and pictures. Is there:

  • A hammer mill
  • A hydraulic press
  • A clay mixer
  • A pug mill
  • Potters wheels
  • A kiln (please indicate interior size, type of fuel used, and firing temperature)
  • Production and storage space (indicate square footage of each)
  • Shelving for 1000 filters

The Workshop:

  • Date established
  • Type of production
  • Forming or production method(s) utilized
  • Number and size of kilns
  • Equipment currently installed
  • Electrical: Voltage and amperage available
  • Water availability
  • Number of men and women workers
  • Vehicles
  • How is pottery presently is marketed and distributed?

Potters Without Borders wants to work with you to create a social enterprise that will be not only sustainable, but profitable for all involved, and especially to the benefit of those most in need of potable drinking water. We have found that the presence of the above conditions all contribute to a successful project, but we recognize that you may not initially be able to obtain them all without help. Please let us know which of these items you will be able to put in place yourself, and which items you think will require our assistance. We look forward to your questions.

Quantification of the Lifetime of Ceramic Pot Filters

by L. A. Hubbel, (Department of Geological Engineering, Missouri University of Science and Technology, 1400 N. Bishop Ave., 124 McNutt Hall, Rolla, MO 65409 E-mail: lhm7f@mst.edu) and A. C. Elmore, (Department of Geological Engineering, Missouri University of Science and Technology, 1400 N. Bishop Ave., 124 McNutt Hall, Rolla, MO 65409 E-mail: elmoreac@mst.edu)

Document type: Conference Proceeding Paper
Part of: World Environmental and Water Resources Congress 2012: Crossing Boundaries
Abstract: Ceramic pot filters (CPFs) are effective, low-cost household water treatment devices. CPF lifetime is assumed by the manufacturer to be one year; however, there are no definitive studies which quantify CPF lifetime. The objective of this preliminary research was to quantify the lifetime of a CPF in terms of the amount of water that can be filtered before the flow rate becomes unusable. Constant head flow rate testing, porosity testing and water quality testing were performed in a laboratory using three CPFs to establish baselines for comparison with field tests using six CPFs manufactured in Antigua, Guatemala. Interviews with 17 CPF users were performed in Guatemala to obtain information on their water and CPF usage. The limited laboratory and field testing showed that flow rate values decreased with increasing cumulative volumes of treated water. The field test data was compared to the laboratory data to estimate the volume of water that would be filtered before the flow rate decreased to an unusable rate. This volume was found to be approximately 1,500 L, which corresponds to a six-month time for a family of six using World Health Organization estimates of daily water consumption. The water quality data collected in the field showed that turbidity decreased after filtering through the CPFs while conductivity and hardness both increased slightly. This increase in conductivity and hardness may be due to rainwater being used as the water source, which typically has low mineral content with very little dissolved solids and hardness to begin with. The number of families interviewed is too small of a data set to provide conclusive results. But the anecdotal data collected from the interview process suggests that the subject families did not believe that a single filter could provide enough drinking water for a family for one year. The large number of CPFs in use throughout the world means that the technology has the potential to have a significant impact on large number of people, and it is recommended that a formal study involving large numbers of filters be conducted to quantitatively estimate CPF lifetimes.


LPG Burner Calculations

http://www.combust.com.au/ceramics/kiln/kiln.htm : A rough rule-of-thumb ratio is one square inch of flue
area to 8,000 BTU’s of maximum gas input

from: http://www.wardburner.com/technicalinfo/samplecalculations.html

There are several variables that come into play when choosing burners for a kiln or furnace. Listed below
are the facts you need to know before deciding the size (Btu’s per Hour) of your burner system.

1. Total inside volume of the kiln.
2. Type of wall construction.
3. Maximum temperature you will be reaching.

Calculating Kiln Volume
Kiln volume is usually expressed in Cubic Feet (CF). In a flat top kiln this figure is arrived at by multiplying
the interior height (H) by the interior width (W) by the depth or length (L).

Sprung or Roman arch: CF = W x L x (Side wall + 2/3 of the arch rise)
Catenary arch: CF = L x Arch area (4/3 H x 1/2 Base Width)
Barrel kiln: CF = H x Pi x R2 (R2 – Radius is 1/2 the diameter x itself) (Pi = 3.14)

If you have used inches in the above equations, divide the total by 1728 to convert to Cubic Feet.

Wall Construction & Temperature
The type of material and its’ insulating values determines how many Btu’s per Cubic Feet per Hour (Btu/
Cf/Hr), you will need to reach a desired temperature. Below is a simplified chart showing materials,
desired temp., and the corresponding Btu/Cf/Hr. There are a host of variables that can affect kiln
efficiency. This is a basic guide only.


9″ Hard Brick

9″ Insultating Brick

6″ Ceramic Fiber

This simple table gives you an idea of how many Btu’s per Cubic Feet per Hour you will need. Multiplying
this figure by the total Cubic Feet will give you Btu/Hr. Now divide Btu/Hr by the number of burners you
plan to use to determine what Btu/Hr rating each burner should have. The numbers above show a range
of BTU figures. The highest figure in each range produces a 6-7 hour firing. The lowest figure will produce
firings in the 14-18 hour range. I feel it is better to have extra Btu’s than not enough. The above is a guide
not a guarantee. If you would like us to verify your calculations, please feel free to call or write.

Cone 06




Cone 6




Cone 10




Raku Construction & Btu/Hr Values

Many folks don’t realize that Raku kilns have much higher Btu input rates than stoneware kilns. This is
because Raku is traditionally done very quickly. For this reason, it is very difficult to bisque fire in a Raku
kiln. If you plan on purchasing or making a Raku kiln, please note that you could have problems with
steam explosions of the ware if you attempt to use the kiln for bisque. Also, the structural nature of Raku
kilns make many of them impractical for use at stoneware temperatures. The chart below gives the basic
Btu input for Raku kilns of various materials. These input values are for a fast firing rate of around 20-30
minutes for the first load. Subsequent loads would be slightly faster.


4 1/2″ Hard Brick

2 1/2″ Insulating Brick

4 1/2″ Insulating Brick

1″ Ceramic Fiber

2″ Ceramic Fiber







Sample Calculations & Burner Options

Flat Top Kiln: 45″ H • 45″ W • 45″ L. Constructed of 9″ insulating brick.

45 x 45 x 45 = 91,125 cu/in. divided by 1728 = 53 cu/ft (aprox.)
For cone 10 firing of 6-8 hours – 53 x 16,000 = 848,000 Btu/HR

For 2 Burners – 848,000 ÷ 2 = 424,000 per burner

For 4 Burners – 848,000 ÷ 4 = 212,000 per burner

For 6 Burners – 848,000 ÷ 6 = 141,333 per burner

Sprung Arch Kiln: (30″H + 5″ RISE) • 30″ W • 30″ Hard Brick construction

(30 + [.66 x 5]) = 33.3 x 30 x 30 = 29,970 cu/in divided by 1728 = 17.5 cu/ft
For cone 10 firing of 6-8 hours – 17.5 x 20,000 = 350,000 Btu/HR

For 2 Burners – 350,000 ÷ 2 = 175,000 Btu per burner

For 4 Burners – 350,000 ÷ 4 = 87,500 Btu per burner

For 6 Burners – Not necessary

Catenary Arch Kiln: 40″ W • 48″ H • 60″ L Insulating brick w/2″ ceramic fiber

([4/3 x 48]=64) x ([1/2 x 40]=20) x 60 = 76,800 cu/in divided by 1728 = 44.5 cu/ft
For cone 10 firing of 6-8 hours – 44.5 x 12,500 = 556,250 Btu/HR

For 2 Burners – 556,250 ÷ 2 = 278,125 Btu per burner

For 4 Burners – 556,250 ÷ 4 = 139,062 Btu per burner

For 6 Burners – 556,250 ÷ 6 = 92,608 Btu per burner

55 Gallon Drum Kiln: 18″ D • 32″ H Lined with 2″ ceramic fiber

([18 ÷ 2] = 9{radius} squared (9×9) x Pi (3.14) x 32 = 8,139 cu/in divided by 1728 = 4.7 cu.ft..
For Raku firing of 20-30 minutes – 4.7 x 20,000 = 94,000 Btu/HR

1 Burner Adequate

Ward Burner Systems
PO Box 1086 • Dandridge, TN • 37725
(865) 397-2914 phone • (865) 397-1253 fax


from: http://www.combust.com.au/ceramics/Charts.htm


Based on required capacity of 50MJ/m2 (4500 BTU/ft2) per hour for cubic kilns lined with 150 mm (6″)
of ceramic fibre. The area on which the calculations are based is the total internal surface area of the kin
space, not the stacking space only.
Example: 20 cubic foot (total volume) fibre kiln to 1300oC uses approx. 210,000 BTU/hour at top
temperature therefore use 2 x LK32 burners or 4 x LK25 burners for more even heat.


Download (DOC, 132KB)

Use of Ceramic Water Filters in Cambodia

Ceramic filter pilot projects (2002-2006) in Cambodia have yielded promising results that suggest these
interventions can be effective in improving drinking water quality and can contribute to substantial
health gains in populations using them.

“Executive Summary
Household-scale ceramic filtration technology is considered among the most promising options for treating drinking water at the household level in developing countries (Lantagne 2001; Sobsey 2002; Roberts 2004). Its use is Cambodia is widespread and growing, with the involvement of local and international NGOs and government efforts that have been supported by UNICEF, WSP-Cambodia, and others. Although several different kinds of ceramic filters are used for household-scale water treatment worldwide, among the most widespread is that promoted by Potters for Peace, a US and Nicaragua-based NGO; the Cambodian version is known as the Ceramic Water Purifier (CWP). It has been used in Cambodia since its introduction in 2001. Based on early successes in Cambodia (Roberts 2004), further investment in the technology is planned by NGOs and the Cambodian government. Stakeholders identified evaluation of the CWP experience to date in the country as vital to inform the scale up process and to identify lessons learned in the first 4 years of production and implementation. Part of this evaluation was an independent study commissioned by UNICEF and WSP-Cambodia to critically examine two major implementation efforts to date in Cambodia undertaken by the two main producers, IDE and RDI. The goals of the study were to characterize the microbiological effectiveness and health impacts of the CWP in target populations, and to identify successes and potential challenges facing the scale-up and implementation of the technology. The results of the study and program recommendations are presented here.”


Rwanda: Projet de filtre à  eau en céramique 2010

Une filme par: Debra Brosseuk
Projet de coopération du Potiers Sans Frontières, KIST (Kigali Institut de la Science et
Technologie), UNICEF, et  KACYIRU Cooperative Moderne de Poteries.

Guy Mbayo K. (Unicef WASH Program)
Burt Cohen (Potiers Sans Frontières)
Phocus Ntayombya (Unicef WASH Program)
Eugene Dusingizumuremyi (KIST Project Director)
Vice Rector John Mshana (KIST)
Dr. Jane Muita (Deputy Representative for UNICEF)
Honorable Minister Collette Ruhamya
Jean Paul (President de la Cooperative Moderne de Poterie)
Mugisha Esri (KIST Filter Production Officer) Continue reading “Rwanda: Projet de filtre à  eau en céramique 2010”