膨潤土(bentonite)按譯音、成因及用途又稱斑脫巖、膨土巖等，是以蒙脫石(也稱微晶高嶺石、膠嶺石)為主要成分的粘土巖—蒙脫石粘土巖,常含少量伊利石、高嶺石及沸石、長石、方解石等。蒙脫石為少量堿及堿土金屬的含水鋁硅酸鹽礦物。

由于蒙脫石層間水和層間可交換陽離子存在，按蒙脫石所含可交換陽離子種類、含量和結(jié)晶化學(xué)性質(zhì)等,可將膨潤土劃分為鈉基膨潤土(堿性土)、鈣基膨潤土(堿土性土)和天然漂白土(酸性土或酸住白土)三種。

物理性質(zhì)：

顏色一般為白色,淡黃,因含鐵量變化又呈淺灰、淡綠粉紅、褐紅、黑雜等色。具蠟狀、土狀或油脂光澤。

化學(xué)成份：

膨潤土的主要化學(xué)組分是二氧化硅(sio2),三氧化二鋁(al2o3)和水。氧化鐵和氧化鎂含量有時也較高。此外,鈣、鈉、鉀等常以不同含量存在于膨潤土中。膨潤土的na2o和cao含量對膨潤土的物理化學(xué)性能和工藝技術(shù)性能影響頗大。

理化性能：

膨潤土具有吸濕性，能吸附8～15倍于本體積的水量。吸水后膨脹，能膨脹數(shù)倍，可達(dá)30余倍。在水介質(zhì)中能分散呈膠體懸浮液，這種懸浮液具有一定的粘滯性、觸變性和潤滑性。它和水、泥或砂等細(xì)碎屑物質(zhì)的摻合物有可塑性和粘結(jié)性。有較強的陽離子交換能力。對各種氣體、液體、有機物質(zhì)有一定的吸附能力，Zui大吸附量可達(dá)5倍于它的重量，具有表面活性的酸性漂白土能吸附有色物質(zhì)。

 膨潤土的理化性能主要取決于它所含的蒙脫石種類和含量。一般鈉基膨潤土較之鈣基或鎂基膨潤土的物理化學(xué)性質(zhì)和工藝技術(shù)性能優(yōu)越。主要表現(xiàn)在：吸水速度慢，但吸水率和膨脹倍數(shù)大；陽離子交換量高；在水介質(zhì)中分散性好，膠質(zhì)價高；它的膠體懸浮液觸變性、粘度、潤滑性好，ph值高；熱穩(wěn)定性好；有較高的可塑性和較強的粘結(jié)性；熱濕拉強度和干壓強度高。所以鈉基膨潤土的使用價值和經(jīng)濟價值較高。

鈉基膨潤土的應(yīng)用：

①在機械鑄造業(yè)中，可作鑄造型砂、粘結(jié)劑，可以克服鑄件的“夾砂”“起皮”現(xiàn)象，降低鑄造件廢品率，保證鑄件的精度和光潔度。

②在造紙工業(yè)中，用作紙張的填充劑，增強紙張的光亮度。

③利用本產(chǎn)品的強粘結(jié)性能，用于白乳膠、地板膠、漿糊等的制作。

④因其有穩(wěn)定的懸浮性、增稠性，能有效地托浮分散粉體，可作水性涂料的增稠防沉淀助劑。

⑤同時利用它的優(yōu)良的分散性和膨脹性，高造漿率、低失水量及膠體性能和剪切稀釋能力，可以用作鉆井泥漿用鈉土。

鑄造性能：

項目指標(biāo)級別

熱濕拉強度

濕壓強度

膠體率

膨脹倍數(shù)

200目通過量

含水率

造漿率

mpa

mpa

%

%

%

一級

2.5

0.0049

100

25~30

95

≤10

≥16

二級

2~2.5

0.00294~0.0049

100

18~25

90

≤12

≤15

乳膠、涂料性能指標(biāo)：

項目

白度

粘度

膠質(zhì)價

ph值

水份

膨脹容

粒度

%

ps

ml/15g±

%

ml/g±

指標(biāo)

≥75

≥2.8

≥90

8~10

≤10

≥20

300~325

英文版the english version

sodium machine swelling soil

bentonite clay (bentonite) in transliteration,causes and use is also called spot to take off the rock, bentonite,etc., is based on montmorillonite (also known as microcrystallinekaolinite, montmorillonite) as the main component of clay rock -montmorillonite clay rock, often contain small amounts of illiteand montmorillonite, zeolite, feldspar, calcite, etc.montmorillonite is a small amount of alkali and alkaline earthmetal hydrous aluminum silicate minerals.

because of montmorillonite interlayer water andinterlayer exchangeable cations, in accordance with themontmorillonite content of exchangeable cation type, content andcrystal chemistry, etc., can be divided into sodium base bentonitebentonite (alkaline soil), calcium base bentonite (alkali) nativesoil and natural bleaching earth lived (acidic soil or clay) threekinds.

physical properties:

color general for white, weak yellow, because ofiron content change in light grey, light green, pink, brown color,red, black etc. with waxy luster, earthy or grease.

chemical composition:

bentonite silica (sio2) is the main chemicalcomposition, 3 oxidation 2 aluminium (al2o3) and water. iron oxideand magnesium oxide content sometimes higher. in addition, calcium,sodium, potassium, etc often exist in different content inbentonite. bentonite na2o and cao content on the physical andchemical properties of bentonite and technology performanceuite big.

the physical and chemical properties:

bentonite has hygroscopicity, can adsorption 8 ~ 15times the volume of water. after water absorption expansion, canexpand to several times, can reach more than 30 times. that candisperse in water medium in colloidal suspension, the suspensionhas certain viscosity, thixotropy and lubricity. it with water, mudor sand and fine detrital material blending has plasticity andsintering. has the strong cation exchange capacity. for a varietyof gases, liquids, has certain adsorption ability of organicmatter, up to 5 times the maximum adsorption of its weight, has thesurface activity of the acid bleaching earth can adsorptionnon-ferrous material.

physico-chemical properties of the bentonitecontained mainly depends on its content and the types of themontmorillonite. general sodium base bentonite than calcium ormagnesium based bentonite technologies of chemical and physicalproperties and superior performance. mainly displays in: the waterabsorption speed is slow, but multiple large water absorption rateand inflation; high cation exchange capacity; good dispersibilityin water medium and high colloid valence; its thixotropy andviscosity, good lubricity, colloidal suspension of high ph value;good thermal stability; have higher plasticity and strong cakingproperty; hot wet tensile strength and high dry strength. so theuse of sodium base bentonite value and economic value ishigher.

the application of sodium base bentonite:

(1) in the mechanical casting industry, as a foundrysand, binder, which can overcome the "sand" of casting "peelingphenomenon, reduce the casting scrap rate, ensure the accuracy ofcastings and finish.

(2) in the papermaking industry, is used as paperfiller, enhance the brightness of paper.

3. use of this product strong bonding performance,production for white latex, floor glue, paste, etc.

(4) because of its stable levitation, thickening,can effectively support distributed powder, as a water-based paintthickening additives precipitation.

5. at the same time take advantage of its excellentdispersibility and expansibility, high mud making rate, low fluidloss and colloidal properties and shear dilution ability, can beused as a drilling mud used sodium soil.

the casting performance:

project target level

hot wet tensile strength

wet strength

colloid rate

expansion ratio

200 mesh by volume

the moisture content

mud making rate

mpa

mpa

%

%

%

level 1

2.5

0.0049

100

25 to 30

95

10 or less

16 or higher

the secondary

2-2.5

0.00294 ~ 0.0049

100

18 ~ 25

90

12 or less

15 or less

emulsion, coating performance indicators:

project

white degree

viscosity

colloid valence

the ph

the moisture

expansion of capacity

particle size

%

ps

15 ml/g -

%

ml/g -

indicators

75 or more

2.8 or higher

90 or more

8 ~ 10

10 or less

two or more

300-325