Product Description: Fire Assay Clay Crucible

Model No.: 30G, 40G, 50G, 55G, 65G, 75G

Multi-use Times: More Than 5 Times

Package Type: Crates or Cartons with Pallet

Order Lead Time: 3 Days

Delivery Port: Qingdao Port or Shenzhen Port

Customization Availability: Yes


Please review below detail information to know more about Decent fire assay clay crucibles.Product Details



Fire assay clay crucible is made of fire clay and proprietary additives and has more than 3000 years history in both historical texts and gold refining industry. A crucible is, in simple term, a ceramic cup. So it is also called “pot”.

A modern fire assay clay pot is not so far removed from those of the past with the exception of the additional science and technology behind its compositions. Modern fire assay crucibles are designed and manufactured for mineral and geochemical laboratories’ usage rather than refining and so are required to be exacting in their specifications and strong enough to withstand huge changes in temperature through multiple uses.

Different from offering one shot disposable crucible, we produce and provide fire assay clay crucibles which have well-deserved reputation for multiple firings uses. Our standard range of fire assay clay crucibles from 30G to 75G can usually be proceeded 5-times-firing and sometimes can be even repeatedly used in more than 9 times with some formula of flux. This feature provides our customers important benefits of reducing cost per firing and increasing profitability. And we can also design and supply to our customer's individual requirements and specifications in dimensions, shape and so on.


We have more than 20 years experiences in the industrial ceramic and refractory industry, including fire assay clay crucible, cupel and so on. Our current factory plant of industrial ceramic and refractory products is around 30,000 square meters (around 8 acres) which includes one office building, three production workshops and one warehouse. Our current annual production capacity of crucible is 6.5 million pieces and can be expanded to more than 9 million if necessary.


We manufacture fire assay multi-firing clay crucibles with the latest automated technology and so we can guarantee sizing consistency which is critical for multi-pour systems and automated lines in fire assay laboratories. Meanwhile, carefully selected raw materials and more reasonable formulation with low caustic soda, low iron content and high silicon content enable our fire assay clay crucibles to have high temperature resistance up to 1500°C. The ingredients of crucible are as below sheet.

Ingredient Percentage (%)
Silica (SiO2) 60-65
Magnesium Oxide <0.2
Calcium Oxide <0.6
Aluminum Oxide 30-34
Ferric Oxide <2
Titanium Oxide <2
Sodium Oxide <0.1
Potassium Oxide <0.5

What's more, we are the only manufacturer in China which has complete in-house capability for all production processes of fire assay clay pots. This ensures best control in quality, cost and order lead time from the beginning of production. So we keep supplying multiple firing fire assay clay pots to many well-known fire assay laboratories in all over the world. Below are some photos of production procedure and process. 图片2.png Ball Milling Raw Materials Compression Filtration

图片3.pngVacuum Pugging图片4.png




图片6.png图片7.png   Chain Drying Firing Firing


Customization is also available for any requirement to shape, size and so on. We can even mold logo, model no. or other signs onto the bottom of crucible if it is required by customer.


We have very strict quality control and inspection procedure and standard to every batch of crucibles. Following process is applied to all batches of pots we produce and supply.

Visual Check & Inspection: Fire assay clay pots are randomly selected from crates package according to sampling rate. All randomly selected pots are weighed to check weight variability. Then the durability of pots is tested by striking the pots increasingly harder. After these tests, the randomly selected fire assay clay pots are cut in half to provide a cross section, which enables QC to check the consistency of grain size and external profile in height and width.

Use Test: Randomly selecting some pots again according to sampling rate and then adding flux without silica in pots to ensure the pots are tested aggressively. Then placing these crucibles into fusion furnace which has been set at 1050°C for 1 hour to replicate normal fusion conditions. This process is repeated in 5 times. The final test result can be recorded as Pass if no noticeable difference in pouring is observed among the pots and no lead splashing on the moulds occurred and no any structural damage, i.e. cracks or holes in the walls, to the crucibles.

 图片9.png图片10.pngReplicate Normal Fusion Conditions for Use Test Crucible Status after 5 Times Firing

Above photo is the status of our fire assay clay crucibles after 5 fires which has no any structural damage (Borax constituent of flux attacks the material of crucible and can cause structural defects) and no any showed signs of being compromised i.e. cracks or holes in the crucible walls. From the photo we can notice that the crucible walls are less eroded and still appear smooth appearance. All these approve the premium quality and multiple firings feature of Decent fire assay clay crucible.

 图片11.png Boil Over Status after 5 Times Firing

Above photo shows the boil over status of our fire assay clay crucibles after 5 fires, which show less evidence of boil over and also approves the premium quality and excellent multi-trip feature of Decent fire assay clay crucibles.


After all tests have been done and final result is Pass, the related batches of crucibles will be put into wooden crates or cartons with pallet according to customers’ requirements. Both carton and crate can be printed with customer’s Logo or shipping marks according to customers’ requirements. Then QA stamp and production serial no. will be marked onto the packages before container loading or delivering to port.  


We keep stock for almost all models of crucible in the warehouses at both our production facility and Qingdao port for various consignment deliveries requirements to any location around the world. The shortest order lead time and delivery time can be 3 days after receiving order confirmation, which ensures on time and in full delivery for any urgent order.


We ship hundreds of containers of crucibles to all over the world. So we have rich experience for container loading to meet various requirements to FCL shipment such as followings:

Only one model of crucible and all crucibles are packed into crates and then loaded into container.

Only one model of crucible and all crucibles are packed into cartons with pallet and then loaded into container.

Only one model of crucible and all crucibles are packed into cartons without pallet and then loaded into container.

Various models of crucible and some models are packed into crate and some are packed into cartons with pallet and then loaded all crates and pallets into container.

Various models of crucible and some models are packed into crate and some are packed into cartons without pallet and then loaded all crates and cartons into container.

Various models of crucible and some models are packed into crate, some are packed into cartons with pallet and some are into cartons without pallet. Then load all crates, pallets and cartons into container.


Besides the models and dimensions of fire assay clay pots listed below, we are also able to produce any model and size of fire assay clay pots according to customer's requirements.

Model No.





Top OD




Base OD


Pcs / Crate Pcs / Container
DC30 30G 245 85 107 55 2600 52,000
DC40 40G 350 88 130 55 2000 40,000
DC50 50G 430 105 150 57 1530 30,060
AP A Pot 455 105 132 57 1290 25,800
DC55 55G 470 88 155 57 1500 30,000
DC65 65G 500 105 165 57 1425 28,500



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