ART
BEAUTY & WELLNESS
CRAFT
CULTURE & HISTORY
ENTERTAINMENT
ENVIRONMENT
FOOD & DRINKS
REVERSE ENGINEERING
SCIENCES
SPORTS
TECHNOLOGY
WEARABLES
Barium Ferrite Disc Magnet from Natural Magnetite, Presintered at 900 °C (Went, Philips 1956, Ex. 36, Procedure 1)
A barium ferrite magnet made from natural magnetite instead of ferric oxide: barium carbonate and magnetite ground 18 hours, presintered 3 hours at 900 °C, ground again 18 hours, pressed and sintered 2 hours at 1200 °C. Went's rod held 1,450 gauss with a coercive force of 2,425 oersted.
Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 36. They sintered rods; discs and the magnetising are ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.
Advanced
2 days
Instructions
1
1
Weigh barium carbonate and magnetite
Weigh barium carbonate and magnetite
Weigh 9.9 g barium carbonate (0.05 mol) and 46.9 g natural magnetite, Fe3O4 (0.20 mol). Barium carbonate is poisonous if swallowed: gloves and a dust respirator.
Materials for this step:
Barium Carbonate (Witherite)9.9 g
Magnetite46.9 gTools needed:
Balance Scale
Rubber Gloves
P100 Respirator2
2
Grind 18 hours in a ball mill
Grind 18 hours in a ball mill
Grind the mixture in a ball mill for 18 hours. The patent does not say whether wet or dry.
Tools needed:
Iron Ball MillP100 Respirator3
3
Presinter at 900 °C for 3 hours
Presinter at 900 °C for 3 hours
Fire the ground mixture at 900 °C for three hours and let it cool.
Tools needed:
Muffle Furnace
Crucible with Lid (Porcelain)
Crucible Tongs
Heat-Resistant Gloves4
4
Grind 18 hours in a ball mill
Grind 18 hours in a ball mill
Grind it again in a ball mill for 18 hours. The patent does not say whether wet or dry.
Tools needed:
Iron Ball MillP100 Respirator5
5
Press at 1.5 t/cm²
Press at 1.5 t/cm²
Press at 1.5 tonnes per cm² (ours: discs instead of a rod).
Tools needed:
Hydraulic Press
Disc Pressing Die6
6
Sinter at 1200 °C for 2 hours
Sinter at 1200 °C for 2 hours
Sinter at 1200 °C for 2 hours. The patent gives no atmosphere for this example. Went's rod: 1,450 gauss, 2,425 oersted.
Tools needed:
Muffle FurnaceCrucible TongsHeat-Resistant Gloves7
7
Magnetise the discs
Magnetise the discs
The patent gives no magnetising method. Ours: lay a disc with its faces against the poles of a strong electromagnet, switch the current on, then off. Find which face is north with a compass.
Tools needed:
Electromagnet
CompassTools Required
12- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
This blueprint makes
Related Blueprints
These blueprints share knowledge with this one — techniques, materials, or principles that connect them in the learning graph.
CC0 Public Domain
This blueprint is released under CC0. You are free to copy, modify, distribute, and use this work for any purpose, without asking permission.
Support the Maker by purchasing products through their Blueprint where they earn a Maker Commission set by Vendors, or create a new iteration of this Blueprint and include it as a connection in your own Blueprint to share revenue.